Autoionization of Water

Size: px
Start display at page:

Download "Autoionization of Water"

Transcription

1 Water itself is a weak acid and weak base: Two water molecules react to form H 3 O + and OH - (but only slightly) H 2 O H 2 O H 3 O + OH - Autoionization of Water H 2 O (l) + H 2 O (l) H 3 O + (aq) + OH - (aq) [H 3 O + ][OH - ] K = [H 2 O] 2 The ion-product for water, K w : = [H + ][OH - ] = K w Set = 1.0 since nearly pure liquid water even when salts, acids, or bases present. K = K w = [H 3 O + ][OH - ] = 1.0 x (at 25 o C) For pure water the concentration of hydroxyl and hydronium ions must be equal: [H 3 O + ] = [OH - ] = 1.0 x = 1.0 x 10-7 M (at 25 o C) 1

2 The Meaning of K b, the Base Dissociation Constant For the generalized reaction between a base, B(aq), and water: B (aq) + H 2 O (l) BH + (aq) + OH - (aq) Equilibrium constant: K = K b = [BH + ][OH - ] [B] The stronger the base, the higher the [OH - ] at equilibrium and the larger the K b. The Relation Between K a and K b for a Conjugate Acid-Base Pair Acid HA + H 2 O H 3 O + + A - Base A - + H 2 O HA + OH - 2 H 2 O H 3 O + + OH - [H 3 O + ] [A - ] [HA] x [HA] [OH - ] = [H 3 O + ] [OH - ] [A - ] K a x K b = K w For HNO 2 : K a = 4.5 x 10-4 and for NO - 2 : K b = 2.2 x K a x K b = (4.5 x 10-4 )(2.2 x ) = 9.9 x or ~ 10 x = 1 x = K w 2

3 ph of a Strong Acid Calculate ph of 1.0 M HClO 4 major species : H +, ClO 4 - and H 2 O perchloric acid is a strong acid: FULLY dissociated Therefore, 1.0 M HClO M H + ph = - log [H + ] = - log [1.0] = 0.00 Calculate ph of 0.01 M HClO 4 ph = - log [H + ] = - log [0.01] = 2.0 Calculate ph of 0.02 M HClO 4 ph = - log [H + ] = - log [0.02] = 1.7 Two New Definitions Remember: K w = [H+][OH-] so that [OH-] = K w / [H+] 1) poh = -log [OH-] = - log (K w /[H + ]) = - log K w (- log [H + ]) = pk w ph = - log (1.0 x ) ph poh = ph 2) It is convenient to express equilibrium constants for acid dissociation in the form pk a = - log K a 3

4 ph of a Strong Base Calculate ph of 1.0 M NaOH major species : Na +, OH - and H 2 O sodium hydroxide is a strong base: FULLY dissociated Therefore, 1.0 M NaOH 1.0 M [OH - ] ph = - log [H + ]; poh= - log [OH - ]; pk w = ph + poh = 14 ph = 14 poh ph = 14 (-log 1.0) = 14.0 Calculate ph of 0.01 M NaOH ph= 14 (-log 0.01) = 14 2 = 12.0 Calculate ph of 0.02 M NaOH ph= 14 (-log 0.02) = = 12.3 Calculating [H 3 O + ], ph, [OH - ], and poh Problem: A chemist dilutes concentrated hydrochloric acid to make two solutions: (a) 3.0 M and (b) M. Calculate the [H 3 O + ], ph, [OH - ], and poh of the two solutions at 25 o C. Solution: (a) [H + ] = 3.0 M ph = -log[h + ] = -log(3.0) = [OH - ] = K w = 1 x = 3.3 x M [H + ] 3.0 poh = - log(3.3 x ) = (b) [H + ] = M ph = -log[h + ] = -log(0.0024) = 2.62 [OH - ] = K w = 1 x = 4.2 x M [H + ] poh = -log(4.2 x ) =

5 ph= -log[h + ] poh= - log [OH - ] pk w = 14 = ph + poh K w = [H + ][OH - ] Remember The Acid-Dissociation Constant (K a ) Acids dissociate into ions in water: HA (aq) + H 2 O (l) HA (aq) H 3 O + (aq) + A - (aq) H + (aq) + A - (aq) K a = [H 3 O + ][A - ] [HA] = [H + ][A - ] [HA] In a dilute solution of a WEAK acid, most of HA remains undissociated and therefore [HA] init = [HA] eq K a = [H + ][A - ]/[HA] = [H + ] 2 / [HA] init 5

6 Calculate the ph of a 1.00 M HNO 2 Solution Problem: Calculate the ph of a 1.00 M solution of nitrous acid HNO 2. Solution: HNO 2 (aq) H + (aq) + NO 2 - (aq) K a = 4.0 x 10-4 Initial concentrations: [H + ] = 0, [NO 2- ] = 0, [HNO 2 ] = 1.00 M Final concentrations: [H + ] = x, [NO 2- ] = x, [HNO 2 ] = 1.00 M - x [H K a = + ] [NO 2- ] = 4.0 x 10-4 = [HNO 2 ] (x) (x) x Assume 1.00 x 1.00 to simplify the problem. x x 10-4 or x x x = 2.0 x 10-2 = 0.02 M = [H + ] = [NO 2- ] ph = - log[h + ] = - log(2.0 x 10-2 ) = 1.70 Determining Concentrations from K a and Initial [HA] Problem: Hypochlorous acid is a weak acid formed in laundry bleach. What is the [H + ] and ph of a M HClO solution? K a = 3.5 x 10-8 Plan: We need to find [H + ]. First we write the balanced equation and the expression for K a and solve for the hydronium ion concentration. Solution: HClO (aq) + H 2 O (l) H 3 O + (aq) + ClO - (aq) [H K a = + ] [ClO - ] = 3.5 x 10-8 [HClO] Concentration (M) HClO H 2 O H + ClO - Initial Change -x x +x Equilibrium x ---- x x (x)(x) K a = = 3.5 x x Assume (0.125 x) x 2 = x 10-9 x = 6.61 x 10-5 ph = -log(h + ) = -log(6.61 x 10-5 ) =

7 Finding K a for a Weak Acid from the ph I Problem: The weak acid hypochlorous acid is formed in bleach solutions. If the ph of a 0.12 M solution of HClO is 4.19, what is the value of the K a of this weak acid? Plan: We are given [HClO] initial and the ph, which will allow us to find [H 3 O + ] and then the hypochlorite anion concentration, so we can write the reaction and expression for K a and solve directly. Solution: Calculating [H 3 O + ] : [H 3 O + ] = 10 -ph = = 6.46 x 10-5 M Concentration (M) HClO (aq) + H 2 O (l) H 3 O + (aq) + ClO - (aq) Initial x Change -x x +x Equilibrium x x x x Assumptions: [H 3 O + ] = [H 3 O + ] HClO since HClO is a weak acid, we assume (0.12 M x) 0.12 M Finding the K a for a Weak Acid from the ph II HClO (aq) + H 2 O (l) H 3 O + (aq) + ClO - (aq) x = [H 3 O + ] = [ClO - ] = 6.46 x 10-5 M [H 3 O + ] [ClO - ] K a = (6.46 x 10-5 M) (6.46 x 10-5 M) = = 3.48 x 10-8 [HClO] 0.12 M K a = 3.48 x 10-8 In text books it is found to be: 3.5 x 10-8 Checking: 1. For [H 3 O + 1 x 10 ] from water : -7 M x 100 = 0.155% 6.46 x 10-5 M assumptions are OK 2. For [HClO] dissoc : x 100 = % 6.46 x 10-5 M 0.12 M 7

8 Overview: Solving Weak Acid Equilibrium Problems List the major species in the solution. Choose the species that can produce H + and write balanced equations for the reactions producing H +. Comparing the values of the equilibrium constants for the reactions you have written, decide which reaction will dominate in the production of H +. Write the equilibrium expression for the dominant reaction. List the initial concentrations of the species participating in the dominate reaction. Define the change needed to achieve equilibrium; that is, define x. Write the equilibrium concentrations in terms of x. Substitute the equilibrium concentrations into the equilibrium expression. Solve for x the easy way assume that [HA] 0 x [HA] 0 Verify the approximation is valid (5% rule). Calculate [H + ] and ph. Mixtures of Several Acids - I Calculate the ph of a solution that contains 1.00 M HF (K a = 7.2 x 10-4 ) and 5.00 M HOCl (K a = 3.5 x 10-8 ). Also calculate the concentrations of the F- and OCl- ions at equilibrium. Three components produce H + : HF (aq) H + (aq) + F - (aq) K a = 7.2 x 10-4 HOCl (aq) H + (aq) + OCl - (aq) K a = 3.5 x 10-8 H 2 O (aq) H + (aq) + OH - (aq) K a = 1.0 x Even though HF is a weak acid, it has by far the greatest K a, so it will be the dominant producer of H +. Solve for its I.C.E. table first, then use those concentrations in the second most important equilibrium. Move down the list, in each case setting K a = [H + ] [A - ] [HA] = specific value 8

9 Mixtures of Several Acids - II Initial Concentration (mol/l) Equilibrium Concentration (mol/l) [HF] 0 = 1.00 [HF] = 1.00 x [F - ] = 0 x mol HF [F - ] = x [H + ] = ~ 0 dissociates [H + ] = x [H K a = + ] [F - ] (x) (x) = 7.2 x 10-4 = [HF] 1.00-x x Therefore, x = 2.7 x 10-2 [F - ] = [H + ] = x = 2.7 x 10-2 and ph = 1.57 Mixtures of Several Acids - III The concentration of H + comes from the first part of this problem: Initial Concentration (mol/l) Equilibrium Concentration (mol/l) [HOCl] 0 = 5.00 [HOCl] = 5.00 x [OCl - ] = 0 x mol HOCl [OCl - ] = x [H + ] = 2.7 x 10-2 dissociates [H + ] = 2.7 x x [H K a = + ] [OCl - ] (2.7 x 10 = 3.5 x 10-8 = -2 + x) (x) [HOCl] 5.00-x (2.7 x 10-2 ) x 5.00 x = 6.5 x 10-6 M = [OCl - ] Therefore, ph = 1.56 [F - ] = 2.7 x 10-2 M [OCl - ] = 6.5 x 10-6 M 9

10 PERCENT DISSOCIATION amount dissociated (mol/l) % dissociation = x 100 initial concentration (mol/l) x % dissociation = x 100 [HA] o for a given acid, % dissociation increases as the acid is diluted for a weak acid, [H+] decreases with increasing dilution as [HA] does, but % dissociation increases as dilution increases Figure 7.5: Effect of dilution on the percent dissociation and [H+] K a = [H+ ] [A - ] [HA] 10

11 Problem: Calculate the percent dissociation of a 1.00 M hydrocyanic acid solution, K a = 6.20 x HCN (aq) + H 2 O (l) H 3 O + (aq) + CN - (aq) HCN H 3 O + CN - [H 3 O + ][CN - ] Initial 1.00 M 0 0 K a = [HCN] Change -x +x +x Final 1.00 x x x (x)(x) K a = = 6.20 x 10 (1.00-x) -10 Assume 1.00-x 1.00 K a = = 6.2 x x = 2.49 x x 10-5 % dissociation = x 100 = % 1.00 x 2.. N Weak Bases Many compounds with an electron-rich nitrogen are weak bases. The common structural feature is an N atom that has a lone electron pair in its Lewis structure. EXAMPLES: 1) Ammonia (:NH 3 ) 2) Amines (general formula RNH 2, R 2 NH, R 3 N) H 3 C H CH 3 Dimethylamine H 3 C.. N CH 3 CH 3 Trimethylamine H 3 C.. N.. N H H Methylamine H H C 2 H 5 Ethylamine 11

12 General reaction (R is a hydrocarbon group or a H): NR 3 (aq) + H 2 O(l) HNR 3+ (aq) + OH - (aq) K b = [HNR 3+ ] [OH - ] [NR 3 ] Determining ph from K b and Initial [B] I Problem: Ammonia is commonly used cleaning agent and is a weak base, with a K b of 1.8 x What is the ph of a 1.5 M NH 3 solution? Plan: Ammonia reacts with water to form [OH - ]. Calculate [H 3 O + ] and the ph. The balanced equation and K b expression are: NH 3 (aq) + H 2 O (l) NH 4 + (aq) + OH - (aq) K b = [NH 4 + ] [OH - ] [NH 3 ] Concentration (M) NH 3 H 2 O NH 4 + OH - Initial Change -x x +x Equilibrium x ---- x x making the assumption: since K b is small, (1.5 M x) 1.5 M 12

13 Determining ph from K b and Initial [B] II Substituting into the K b expression and solving for x: [NH 4+ ] [OH - ] (x)(x) K b = = = 1.8 x 10-5 [NH 3 ] 1.5 x 2 = 2.7 x 10-5 x = 5.20 x 10-3 = [OH - ] = [NH 4+ ] Calculating ph: K [H 3 O + w 1.0 x ] = = = 1.92 x [OH - ] 5.20 x 10-3 ph = -log[h 3 O + ] = - log (1.92 x ) ph = Polyprotic Acids 13

14 Calculate the ph of 3.00 x 10-3 M Sulfuric Acid Polyprotic acid, more than one proton to lose!!! Multiple K a s H 2 SO 4 (aq) HSO 4- (aq) + H + (aq) K a1 = LARGE HSO 4- (aq) SO 4- (aq) + H + (aq) K a2 = 1.2 x 10-2 Because first dissociation has a very large K a it can be treated as a strong acid (~100% dissociated). Calculate the ph of 3.00 x 10-3 M Sulfuric Acid HSO 4- (aq) SO 4- (aq) + H + (aq) K a = 1.2x10-2 Initial Concentration (mol/l) Equilibrium Concentration (mol/l) [HSO 4- ] 0 = x mol/l HSO - 4 [HSO 4- ] = x [SO 2-4 ] 0 = 0 dissociates [SO 2-4 ] = x [H + ] 0 = to reach [H + ] = x equilibrium From dissociation of H 2 SO 4 [H + ][SO 2-4 ] K a2 = 1.2 x 10-2 ( x)(x) = = [HSO 4- ] ( x) No obvious approximation looks valid, so we must solve with the quadratic formula. 0 = x x 3.6 x b + a = 1 x = - b 2 4ac b = x = 2.10 x a c = -3.6 x 10-5 [H + ] = x = ph = 2.29 Note: Change in [H+] does not violate huge K a for 1 st dissociation: [H 2 SO 4 ] = 0. 14

15 SALTS and their ph sodium acetate (CH 3 COONa) solution is basic CH 3 COO - + H 2 O CH 3 COOH + OH - ammonium chloride (NH 4 Cl) solution is acidic NH H 2 O NH 3 + H 3 O + sodium chloride solution is neutral NaCl + H 2 O Na + + Cl - + H 2 O Effects of Salts on ph and Acidity Salts that consist of cations of strong bases and the anions of strong acids have no effect on the [H + ] when dissolved in water. Examples: NaCl, KNO 3, Na 2 SO 4, NaClO 4, KBr, etc. A salt whose cation alone has neutral properties (such as Na + or K + ) and whose anion is the conjugate base of a weak acid, produces a basic solution in water, since anion captures some H +. Examples: NaF, KCN, NaC 2 H 3 O 2, Na 3 PO 4, Na 2 CO 3, K 2 S, Na 2 C 2 O 4, etc. A salt whose anion alone has neutral properties and whose cation is the conjugate acid of a weak base OR a small and highly charged metal ion will produce an acidic solution in water. Examples: NH 4 Cl, AlCl 3, Fe(NO 3 ) 3, etc. 15

16 See Table 7.6 Like Example I Calculate the ph of a 0.45 M NaCN solution. The K a value for HCN is 6.2 x Solution: Since HCN is a weak acid, the cyanide ion must have significant affinity for protons. CN - (aq) + H 2 O (l) HCN (aq) + OH - (aq) K b = [HCN] [OH- ] [CN - ] The value of K b can be calculated from K w and the K a value for HCN. K = K w 1.0 x K a (for HCN) = b 6.2 x 10 = 1.61 x Initial Concentration (mol/l) [CN - ] 0 = 0.45 [HCN] 0 = 0 [OH - ] 0 = 0 X mol/l CN - reacts with H 2 O to reach equilibrium Equilibrium Concentration (mol/l) [CN - ] = 0.45 x [HCN] = x [OH - ] = x 16

17 Like Example II Thus: [HCN] [OH - ] K b = 1.61 x 10-5 = [CN - = ] (x)(x) x The approximation is not valid by the 5% rule, so you have to use the quadratic equation. x = 2.68 x 10-3 x = [OH - ] = 2.68 x 10-3 M poh = -log [OH - ] = 2.57 ph = poh = = Small and highly charged cations produce acidic solutions in water. Examples: Al 3+, Fe 3+, etc.. 17

18 Predicting the Relative Acidity of Salt Solutions Problem: Determine whether an aqueous solution of iron(iii) nitrite, Fe(NO 2 ) 3, is acidic, basic, or neutral. Plan: The formula consists of the small, highly charged, and therefore weakly acidic, Fe 3+ cation and the weakly basic NO - 2 (anion of the weak acid HNO 2 ). To determine the relative acidity of the solution, we write equations that show the reactions of the ions with water, and then find K a and K b of the ions to see which ion reacts to form H + or OH - to a greater extent. Solution: Writing the reactions with water: Fe(H 2 O) 3+ 6 (aq) + H 2 O (l) Fe(H 2 O) 5 OH 2+ (aq) + H 3 O + (aq) NO 2 - (aq) + H 2 O (l) HNO 2(aq) + OH - (aq) Obtaining K a and K b of the ions: for Fe 3+ (aq) K a = 6 x 10-3 for NO 2 - (aq), K b must be determined: K b of NO - K 2 = w 1.0 x 10 = -14 = 2.5 x K a of HNO x 10-4 Since K a of Fe 3+ > K b of NO 2-, the solution is acidic. Summary: Solving Acid-Base Equilibria Problems List the major species in solution. Look for reactions that can be assumed to go to completion, such as a strong acids/bases dissociating or H + reacting with OH -. For a reaction that can be assumed to go to completion: a) Determine the concentrations of the products. b) Write down the major species in solution after the reaction. Look at each major component of the solution and decide whether it is an acid or a base. Pick the equilibrium that will control the ph. Use known values of the dissociation constants for the various species to determine the dominant equilibrium. a) Write the equation for the reaction and the equilibrium expression. b) Set up the I.C.E. table and define x. c) Compute the equilibrium concentrations in terms of x. d) Substitute the [ ] eq into the equilibrium expression and solve for x. e) Check the validity of the approximation. f) Calculate the ph and other concentrations as required. 18

19 Summary: General Strategies for Solving Acid-Base Problems Think Chemistry. Focus on the solution components and their reactions. It will almost always be possible to choose one reaction that is the most important. Be systematic. Write down all the things you know, including things like the equilibrium expression, list what you can calculate, and list what s needed. Be flexible. Although all acid-base problems are similar in many ways, important differences do occur. Treat each problem as a separate entity. Do not try to force a given problem to match any you have solved before. Look for both the similarities and the differences. Be patient. The complete solution to a complicated problem cannot be seen immediately in all its detail. Pick the problem apart into its workable steps. Be confident. Look within the problem for the solution, and let the problem guide you. Assume that you can think it out. Do not rely on memorizing solutions to problems. In fact, memorizing solutions is usually detrimental because you tend to try to force a new problem to be the same as one you have seen before. Understand and think - don t just memorize. 19

Chapter 7 Acids and Bases

Chapter 7 Acids and Bases Chapter 7 Acids and Bases 7.1 The Nature of Acids and Bases 7.2 Acid Strength 7.3 The ph Scale 7.4 Calculating the ph of Strong Acid Solutions Midterm Exam 2 7.5 Calculating the ph of Weak Acid Solutions

More information

CHAPTERS 15 FAKE TEST QUESTIONS. 1. According to the Brønsted Lowry definition, which species can function both as an acid and as a base?

CHAPTERS 15 FAKE TEST QUESTIONS. 1. According to the Brønsted Lowry definition, which species can function both as an acid and as a base? You might need to know the following K values: CHAPTERS 15 FAKE TEST QUESTIONS CH 3 COOH K a = 1.8 x 10 5 Benzoic Acid K a = 6.5 x 10 5 HNO 2 K a = 4.5 x 10 4 NH 3 K b = 1.8 x 10 5 HF K a = 7.2 x 10 4

More information

Since we will be dealing with aqueous acid and base solution, first we must examine the behavior of water.

Since we will be dealing with aqueous acid and base solution, first we must examine the behavior of water. Acids and Bases Know the definition of Arrhenius, Bronsted-Lowry, and Lewis acid and base. Autoionization of Water Since we will be dealing with aqueous acid and base solution, first we must examine the

More information

Chapter 14 - Acids and Bases

Chapter 14 - Acids and Bases Chapter 14 - Acids and Bases 14.1 The Nature of Acids and Bases A. Arrhenius Model 1. Acids produce hydrogen ions in aqueous solutions 2. Bases produce hydroxide ions in aqueous solutions B. Bronsted-Lowry

More information

ALE 12. Equilibria of Aqueous Solutions of Weak Acids & Weak Bases

ALE 12. Equilibria of Aqueous Solutions of Weak Acids & Weak Bases Name Chem 163 Section: Team Number: ALE 12. Equilibria of Aqueous Solutions of Weak Acids & Weak Bases (Reference: 18.3 18.5 Silberberg 5 th edition) How is the ph of a solution related to the concentration

More information

Chapter 17. How are acids different from bases? Acid Physical properties. Base. Explaining the difference in properties of acids and bases

Chapter 17. How are acids different from bases? Acid Physical properties. Base. Explaining the difference in properties of acids and bases Chapter 17 Acids and Bases How are acids different from bases? Acid Physical properties Base Physical properties Tastes sour Tastes bitter Feels slippery or slimy Chemical properties Chemical properties

More information

Chapter 16: Acids, Bases, and Salts

Chapter 16: Acids, Bases, and Salts Chapter 16: Acids, Bases, and Salts Key topics: ph scale; acid-base properties of water K a = acid ionization constant; K b = base ionization constant Polyprotic acids BrØnsted Acids and Bases Acid: Base:

More information

Acids and Bases: Definitions. Brønsted-Lowry Acids and Bases. Brønsted-Lowry Acids and Bases CHEMISTRY THE CENTRAL SCIENCE

Acids and Bases: Definitions. Brønsted-Lowry Acids and Bases. Brønsted-Lowry Acids and Bases CHEMISTRY THE CENTRAL SCIENCE CHEMISTRY THE CENTRAL SCIENCE Professor Angelo R. Rossi Department of Chemistry Spring Semester Acids and Bases: Definitions Arrhenius Definition of Acids and Bases Acids are substances which increase

More information

Solutions for Ch. 14 Acids and Bases Practice Questions

Solutions for Ch. 14 Acids and Bases Practice Questions s for Ch. 14 Acids and Bases Practice Questions 1. In the following reactions, label the Acid, Base, Conjugate Acid, and Conjugate Base. Also indicate the two conjugate acid-base pairs Plan Your Strategy

More information

PX212CH1516. C MgCO Al(OH) 6. Which of the following acids has the weakest conjugate base in aqueous solution? A) CH 3 COOH B) HOCl C) HF D) HNO 2

PX212CH1516. C MgCO Al(OH) 6. Which of the following acids has the weakest conjugate base in aqueous solution? A) CH 3 COOH B) HOCl C) HF D) HNO 2 C MgCO Al Al(OH) PX212CH1516 1. Which of the following reactions is not readily explained by the Arrhenius concept of acids and bases? A) HCl(g) + NH 3 (g) NH 4 Cl(s) B) HCl(aq) + NaOH(aq) NaCl(aq) + H

More information

Chapter 15 Review. 2. Which is the formula for the hydronium ion? A. OH - B. H 2 O C. H 3 O + D. H 3 O - E. H 2 O +

Chapter 15 Review. 2. Which is the formula for the hydronium ion? A. OH - B. H 2 O C. H 3 O + D. H 3 O - E. H 2 O + Chapter 15 Review Student: 1. Which is not a characteristic property of acids? A. tastes sour B. turns litmus from blue to red C. reacts with metals to yield CO 2 gas D. neutralizes bases E. reacts with

More information

Models of Acids and Bases. The reaction of an acid HA with water to form H 3 O+ and a conjugate base A-. Conjugate Acid/Base Pairs

Models of Acids and Bases. The reaction of an acid HA with water to form H 3 O+ and a conjugate base A-. Conjugate Acid/Base Pairs Models of Acids and Bases ACIDS and BASES Arrhenius Concept: Acids produce H in solution, bases produce OH ion. Brønsted-Lowry: Acids are H donors, bases are proton acceptors. Review Chapter 4 Acids &

More information

Concept Test: Identify the acid/base and conjugate acid and base in each of the following reactions: Indicate who the conjugates are connected to!

Concept Test: Identify the acid/base and conjugate acid and base in each of the following reactions: Indicate who the conjugates are connected to! Concept Tests: Chapter 17 and 18 Identify the acid/base and conjugate acid and base in each of the following reactions: Indicate who the conjugates are connected to! NH 3 + HCl NH 4 +1 + Cl -1 H 2 S +

More information

Chapter 16. Acid-Base Equilibria Acids and Bases: A Brief Review Brønsted-Lowry Acids and Bases. Conjugate Acid-Base Pairs

Chapter 16. Acid-Base Equilibria Acids and Bases: A Brief Review Brønsted-Lowry Acids and Bases. Conjugate Acid-Base Pairs 16.1 Acids and Bases: A Brief Review Arrhenius concept of acids and bases: an acid increases [H + ] and a base increases [OH ]. 16.2 Brønsted-Lowry Acids and Bases In the Brønsted-Lowry system, a Brønsted-Lowry

More information

1. For the equilibrium that exists in an aqueous solution of nitrous acid (HNO 2, a weak acid), the equilibrium constant expression is:

1. For the equilibrium that exists in an aqueous solution of nitrous acid (HNO 2, a weak acid), the equilibrium constant expression is: 1. For the equilibrium that exists in an aqueous solution of nitrous acid (HNO 2, a weak acid), the equilibrium constant expression is: a) K = [H+ ][NO 2 ] [HNO 2 ] b) K = [H+ ][N][O] 2 [HNO 2 ] c) K =

More information

Acids and Bases: A Brief Review

Acids and Bases: A Brief Review Acids and : A Brief Review Acids: taste sour and cause dyes to change color. : taste bitter and feel soapy. Arrhenius: acids increase [H ] bases increase [OH ] in solution. Arrhenius: acid base salt water.

More information

Acid-Base Equilibria. Chapter 17. Concept Check Concept Check Solution

Acid-Base Equilibria. Chapter 17. Concept Check Concept Check Solution Chapter 17 Acid-Base Equilibria Concept Check 17.1 You have prepared dilute solutions of equal molar concentrations of HC 2 H 3 O 2 (acetic acid), HNO 2, HF, and HCN. Rank the solutions from the highest

More information

Bronsted Acids & Bases

Bronsted Acids & Bases Acids and Bases 1 Bronsted Acids & Bases Acid: substance capable of donating a proton (H + ). Base: substance capable of accepting a proton. (definition not dependent on OH - ) 2 Conjugate Pairs CH 3 COOH

More information

Proton Transfer Acids - Base. Dr. Fred Omega Garces Chemistry 201. Miramar College

Proton Transfer Acids - Base. Dr. Fred Omega Garces Chemistry 201. Miramar College 15.2 Acids Base Proton Transfer Dr. Fred Omega Garces Chemistry 201 Miramar College Important Notes: K a when H 3 O + is produced, K b when OH is produced 1 Acids Bases; Proton Transfer BrønstedLowry AcidsBases

More information

Review for Solving ph Problems:

Review for Solving ph Problems: Review for Solving ph Problems: Acid Ionization: HA H 2 O A - H 3 O CH 3 COOH H 2 O CH 3 COO - H 3 O Base Ionization: B H 2 O BH OH - 1) Strong Acid complete dissociation [H ] is equal to original [HA]

More information

Ch Acids and Bases. Arrhenius Definition Acids produce hydrogen ions in aqueous solution. Bases produce hydroxide ions when dissolved in water.

Ch Acids and Bases. Arrhenius Definition Acids produce hydrogen ions in aqueous solution. Bases produce hydroxide ions when dissolved in water. Ch 15-16 Acids and Bases Arrhenius Definition Acids produce hydrogen ions in aqueous solution. Bases produce hydroxide ions when dissolved in water. Limits to aqueous solutions. Only one kind of base.

More information

CHEM 12 Acids and Bases 3/22/2016

CHEM 12 Acids and Bases 3/22/2016 Acids and Bases Name: Expected background knowledge from acids and bases introductory reading: Definitions (Arrhenius, BL) of an acid and base Definitions of conjugate acid and base pairs Properties of

More information

CH 3 NH 2 + H 2 O <=== CH 3 NH 3 + OH - b. CH 3 CH 2 NH 2 + H 2 O <=== CH 3 CH 2 NH OH - c. HC 2 H 3 O 2 + H 2 O <=== H 3 O + -

CH 3 NH 2 + H 2 O <=== CH 3 NH 3 + OH - b. CH 3 CH 2 NH 2 + H 2 O <=== CH 3 CH 2 NH OH - c. HC 2 H 3 O 2 + H 2 O <=== H 3 O + - Sample Test 2 CHAPTER 16 1. Acids and bases can be defined in several ways. Which of the following are definitions of bases according to these definitions? a compound the produces hydronium ions in water

More information

Acids and Bases. Ch a pt e r Aqueous Equilibria: Chemistry 4th Edition McMurry/Fay. MOH(aq) M + (aq) + OH (aq)

Acids and Bases. Ch a pt e r Aqueous Equilibria: Chemistry 4th Edition McMurry/Fay. MOH(aq) M + (aq) + OH (aq) 15 Ch a pt e r Aqueous Equilibria: Acids and Bases Chemistry th Edition McMurry/Fay Dr. Paul Charlesworth Michigan Technological University AcidBase Concepts 01 Arrhenius Acid: A substance which dissociates

More information

Polyprotic Acids <-- Now it s a tough call as to whether polyprotic acids are important enough for their own piece of paper. But you have to know how

Polyprotic Acids <-- Now it s a tough call as to whether polyprotic acids are important enough for their own piece of paper. But you have to know how Weak Acids Weak acids do not dissociated completely in aqueous solutions. They are somewhat stable molecules and therefore there is an equilibrium constant associated with their dissociation. It s called

More information

Chapter 10. Acids, Bases, and Salts

Chapter 10. Acids, Bases, and Salts 1 Chapter 10 Acids, Bases, and Salts 2 Ch 10.1 Arrhenius Acid-Base Theory (also in Chapter Medley) Arrhenius Acids produce Arrhenius Bases produce H + in water OH - in water HCl hydrochloric acid KOH HNO

More information

Sample Exercise 16.1 Identifying Conjugate Acids and Bases

Sample Exercise 16.1 Identifying Conjugate Acids and Bases Sample Exercise 16.1 Identifying Conjugate Acids and Bases (a) What is the conjugate base of each of the following acids: HClO 4, H 2 S, PH 4+, HCO 3? (b) What is the conjugate acid of each of the following

More information

Aqueous Equilibria: Chemistry of the Water World. Chapter Outline

Aqueous Equilibria: Chemistry of the Water World. Chapter Outline Aqueous Equilibria: Chemistry of the Water World Chapter Outline 15.1 Acids and Bases: The BrØnsted Lowry Model 15.2 Acid Strength and Molecular Structure 15.3 ph and the Autoionization of Water 15.4 Calculations

More information

1. Identify the Bronsted-Lowry acids and bases and the conjugate acid base pairs in the following reactions.

1. Identify the Bronsted-Lowry acids and bases and the conjugate acid base pairs in the following reactions. Exercise #1 Brønsted-Lowry s and Bases 1. Identify the Bronsted-Lowry acids and bases and the conjugate acid base pairs in the following reactions. (a) HCl(aq) + H 2 O(l) H 3 O + (aq) + Cl (aq) (b) H 2

More information

Acids and Bases: A Brief Review, see also pp and pp Brønsted-Lowry Acids and Bases 143. The H + Ion in Water

Acids and Bases: A Brief Review, see also pp and pp Brønsted-Lowry Acids and Bases 143. The H + Ion in Water Quiz number 5 will be given in recitation next week, Feb 26Mar 2 on the first part of Chapter 16, to be covered in lectures this week. 16.1 Acids and Bases: A Brief Review 16.2 BronstedLowry Acids and

More information

WEAK ACIDS AND BASES

WEAK ACIDS AND BASES WEAK ACIDS AND BASES [MH5; Chapter 13] Recall that a strong acid or base is one which completely ionizes in water... In contrast a weak acid or base is only partially ionized in aqueous solution... The

More information

Chapter 16 Acid-Base Equilibria. Acids and Bases. What happens when an acid dissolves in water? Acid and base strength. Conjugate acids and bases

Chapter 16 Acid-Base Equilibria. Acids and Bases. What happens when an acid dissolves in water? Acid and base strength. Conjugate acids and bases Chapter 16 Acid-Base Equilibria Learning goals and key skills: Understand the nature of the hydrated proton, represented as either H + (aq) or H 3 O + (aq) Define and identify Arrhenuis acids and bases.

More information

Solutions to Homework Assignment 10 CHM 152 Spring 2002

Solutions to Homework Assignment 10 CHM 152 Spring 2002 Solutions to Homework Assignment 10 CHM 152 Spring 2002 16.3 (a) This is a weak acid problem. Setting up the standard equilibrium table: CH 3 COOH(aq) H + (aq) + CH 3 COO (aq) Initial (M): 0.40 0.00 0.00

More information

Chem 1721 Brief Notes: Chapters 15 and 16

Chem 1721 Brief Notes: Chapters 15 and 16 Chem 1721 Brief Notes: Chapters 15 and 16 Chapter 15: Acids and Bases; Chapter 16: Acid-Base Equilibria Bronstsed-Lowry definitions of acids and bases are based on proton transfer acids are proton donors

More information

Chapter 8: Monoprotic Acid-Base Equilibria

Chapter 8: Monoprotic Acid-Base Equilibria Chapter 8: Monoprotic Acid-Base Equilibria Chapter 6: Strong acids (SA) and strong bases (SB) ionize completely in water (very large K) [H + ] ions produced equals [S.A.] Example: What is the ph of 0.050

More information

CHAPTER 16 (MOORE) ACIDS, BASES AND ACID-BASE EQUILIBRIA

CHAPTER 16 (MOORE) ACIDS, BASES AND ACID-BASE EQUILIBRIA CHAPTER 16 (MOORE) ACIDS, BASES AND ACID-BASE EQUILIBRIA This chapter deals with acids and bases and their equilibria. We will treat acids as proton (H + ) donors in solution and bases as proton acceptors.

More information

WEAK ACIDS AND BASES

WEAK ACIDS AND BASES WEAK ACIDS AND BASES [MH5; Chapter 13] Recall that a strong acid or base is one which completely ionizes in water. HCR! H + + CR NaOH! Na + + OH The above equations fit the Arrhenius definition of acids

More information

Arrhenius Model Acid. Base. Brønsted-Lowry Model Acid. Base. + H O: + H Cl: H O H + [ :Cl: ] -

Arrhenius Model Acid. Base. Brønsted-Lowry Model Acid. Base. + H O: + H Cl: H O H + [ :Cl: ] - Chapter 14 1. Students will be able to define an acid and base in terms of both the Arrhenius and the Bronsted-Lowry definitions and provide examples of each (including examples that follow the Bronsted-Lowry

More information

BRØNSTED ACIDS & BASES

BRØNSTED ACIDS & BASES ACIDS & BASES BRØNSTED ACIDS & BASES BRØNSTED ACIDS & BASES Brønsted acids are proton donors. Brønsted bases are proton acceptors. Amphoteric species can act as either an acid or a base, depending on the

More information

Acids and Bases. Chapter 15. Acids. Bases. A Brønsted acid is a proton donor A Brønsted base is a proton acceptor

Acids and Bases. Chapter 15. Acids. Bases. A Brønsted acid is a proton donor A Brønsted base is a proton acceptor Acids and Bases Chapter 15 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Acids Have a sour taste. Vinegar owes its taste to acetic acid. Citrus fruits contain

More information

Department of Chemistry University of Texas at Austin

Department of Chemistry University of Texas at Austin Preparation for Buffer Problems Supplemental Worksheet KEY Review of Conjugate Acid/Base Pairs Problem #1: Conjugate acid/base pairs are important to salts and buffers. Complete the following table to

More information

1. What is the conjugate acid of each of the following species? 2. What is the conjugate base of each of the following species?

1. What is the conjugate acid of each of the following species? 2. What is the conjugate base of each of the following species? CHEMISTRY 1AA3 PROBLEM SET 2 WEEK OF JANUARY 21, 2002 SOLUTIONS 1. What is the conjugate acid of each of the following species? Base Conjugate acid (a) S 2 HS CH 3 COO CH 3 COOH (c) ClO 2 HClO 2 (d) 2

More information

Acids and Bases. Chapter 10. Solutions for Practice Problems. Student Textbook page 378

Acids and Bases. Chapter 10. Solutions for Practice Problems. Student Textbook page 378 Chapter 10 Acids and Bases Solutions for Practice Problems Student Textbook page 378 1. Problem Hydrogen cyanide is a poisonous gas at room temperature. When this gas dissolved in water, the following

More information

AP Chapter 15 & 16: Acid-Base Equilibria Name

AP Chapter 15 & 16: Acid-Base Equilibria Name AP Chapter 15 & 16: Acid-Base Equilibria Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. AP Chapter 15 & 16: Acid-Base Equilibria 2 Warm-Ups (Show

More information

Chapter 16 Cartoon from: Strong Acid/Base Neutralization

Chapter 16 Cartoon from:  Strong Acid/Base Neutralization Chapter 16 Applications of Aqueous Equilibria Chapter 16 Cartoon from: http://www.nearingzero.net/sci_chemistry.html 1 Strong Acid/Base Neutralization When a strong acid and a strong base react, the products

More information

CHAPTER 14. Acids and Bases

CHAPTER 14. Acids and Bases CHAPTER 14 Acids and Bases 14.1 The Nature of Acids and Bases Arrhenius model Acid supplies H + to an aqueous solution Base supplies OH - to an aqueous solution Bronsted-Lowry model Acid is a proton (H

More information

NH 4 (aq) + HS - 6.Calculate the molarity and normality of 3500 mls of solution that contains 45.0 grams of phosphoric acid, H PO.

NH 4 (aq) + HS - 6.Calculate the molarity and normality of 3500 mls of solution that contains 45.0 grams of phosphoric acid, H PO. Honors Chemistry Study Guide for Acids and Bases 1. Calculate the ph, poh, and [H O ] for a solution that has a [OH - ] = 4.5 x 10-5? [H ] = 2.2 x 10-10 M; ph = 9.65; poh = 4.5 2. An aqueous solution has

More information

This reaction is often abbreviated as: HA(aq) H + (aq) + A (aq)

This reaction is often abbreviated as: HA(aq) H + (aq) + A (aq) CHAPTER FOURTEEN ACIDS AND BASES For Review 1. a. Arrhenius acid: produce H + in water b. Bρrnsted-Lowry acid: proton (H + ) donor c. Lewis acid: electron pair acceptor The Lewis definition is most general.

More information

IV. Acids and Bases. react with metals to produce hydrogen gas

IV. Acids and Bases. react with metals to produce hydrogen gas IV. Acids and Bases Properties of Acids and Bases Acids ph

More information

ionic substances (separate) based on! Liquid Mixtures miscible two liquids that and form a immiscible two liquids that form a e.g.

ionic substances (separate) based on! Liquid Mixtures miscible two liquids that and form a immiscible two liquids that form a e.g. Unit 7 Solutions, Acids & Bases Solution mixture + solvent - substance present in the amount solute - in the solvent solvent molecules solute particles ionic substances (separate) based on! Liquid Mixtures

More information

AP Chemistry- Acids and Bases General Properties of Acids and Bases. Bases- originally defined as any substance that neutralized an acid

AP Chemistry- Acids and Bases General Properties of Acids and Bases. Bases- originally defined as any substance that neutralized an acid AP Chemistry Acids and Bases General Properties of Acids and Bases Acids Electrolyte Taste Litmus Phenolphthalein React with metals to give off H 2 gas H 2 SO 4 (aq) + Mg (s) MgSO 4 (aq) + H 2 (g) Ionize

More information

Chapter 16 Acid-Base Equilibria

Chapter 16 Acid-Base Equilibria Chapter 16 Acid-Base Equilibria Learning goals and key skills: Understand the nature of the hydrated proton, represented as either H + (aq) or H 3 O + (aq) Define and identify Arrhenuis acids and bases.

More information

Name: Class: Date: Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

Name: Class: Date: Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. Class: Date: Chapter 13 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. In the Brønsted-Lowry model an acid is a. a proton donor. b. a proton

More information

3. What is the ph of a 0.42 M formic acid (HCHO 2 ) solution? K a (HCHO 2 ) = A C B D

3. What is the ph of a 0.42 M formic acid (HCHO 2 ) solution? K a (HCHO 2 ) = A C B D 1. Calculate the ph and [OH ] of a 2.2 10 3 M HNO 3 solution. A. ph = 2.66, [OH ] = 2.2 10 11 C. ph = 11.34, [OH ] = 2.2 10 11 B. ph = 2.66, [OH ] = 4.5 10 12 D. ph = 11.34, [OH ] = 4.5 10 12 2. The autoionization

More information

Chem 116 POGIL Worksheet - Week 10 - Solutions Weak Acid and Base Equilibria

Chem 116 POGIL Worksheet - Week 10 - Solutions Weak Acid and Base Equilibria Chem 116 POGIL Worksheet - Week 10 - Solutions Weak Acid and Base Equilibria Key Questions 1. A 0.0100 M solution of a weak acid HA has a ph of 2.60. What is the value of K a for the acid? [Hint: What

More information

Equilibrium 1. Molecular Chapter Ionic (Weak Acid / Base ) - Chapter Ionic ( Insoluble Salts) - Chapter 17

Equilibrium 1. Molecular Chapter Ionic (Weak Acid / Base ) - Chapter Ionic ( Insoluble Salts) - Chapter 17 Equilibrium 1. Molecular ------------------- Chapter 15 2. Ionic (Weak Acid / Base ) - Chapter 16 3. Ionic ( Insoluble Salts) - Chapter 17 STRONG Acids & Bases 1. COMPLETELY IONIZED (a) HCl(aq) H + (aq)

More information

Acid-Base Chemistry. Brønsted-Lowry Acids & Bases

Acid-Base Chemistry. Brønsted-Lowry Acids & Bases Acid-Base Chemistry ν There are a couple of ways to define acids and bases ν Brønsted-Lowry acids and bases ν Acid: H + ion donor ν Base: H + ion acceptor ν Lewis acids and bases ν Acid: electron pair

More information

p3 Recognizing Acid/Base Properties when p11 Recognizing Basic versus Nonbasic

p3 Recognizing Acid/Base Properties when p11 Recognizing Basic versus Nonbasic General Chemistry II Jasperse Acid-Base Chemistry. Extra Practice Problems 1 General Types/Groups of problems: Conceptual Questions. Acids, Bases, and p1 K b and pk b, Base Strength, and using K b or p7-10

More information

This chapter deals with the solution equilibrium when it contain more than one solute.

This chapter deals with the solution equilibrium when it contain more than one solute. Chapter 17 Additional Aspects of Aqueous Equilibria This chapter deals with the solution equilibrium when it contain more than one solute. Consider a solution of acetic acid: Consider a solution of acetic

More information

The Common Ion Effect and Acid/Base Equilibria

The Common Ion Effect and Acid/Base Equilibria The Common Ion Effect and Acid/Base Equilibria Additional Aspects of Acid/Base Equilibria So far, we have examined the equilibrium concentrations of ions in solutions containing a weak acid or weak base

More information

Summary of MQ2 Results: Mean =124 (71 %) Hi = 175. Lo = 32. Your scores will be posted on WebCT

Summary of MQ2 Results: Mean =124 (71 %) Hi = 175. Lo = 32. Your scores will be posted on WebCT Summary of MQ2 Results: Mean =124 (71 %) Hi = 175 Lo = 32 Your scores will be posted on WebCT 16.5 Strong Acids and Bases Strong Acids Strong Bases 16.6 Weak Acids Calculating K a from ph Using K a to

More information

ALE 11. Acids, Bases, poh and ph

ALE 11. Acids, Bases, poh and ph Name Chem 163 Section: Team Number: ALE 11. Acids, Bases, poh and ph (Reference: 18.1 18.3 Silberberg 5 th edition) Why is baking soda basic? The Model: Brønsted-Lowry Acids and Bases Nitric acid satisfies

More information

Chapter 16 questions. b) An Arrhenius acid turns red litmus blue. c) An Arrhenius acid tastes sour.

Chapter 16 questions. b) An Arrhenius acid turns red litmus blue. c) An Arrhenius acid tastes sour. Chapter 16 questions 1. Which of the following statements does not accurately describe a characteristic property of an Arrhenius acid? a) An Arrhenius acid is a substance that increases the concentration

More information

Chapter 17 Additional Aspects of

Chapter 17 Additional Aspects of Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 17 Additional Aspects of This chapter deals with the solution equilibrium when it contain

More information

Define what strong and weak always mean in aqueous chemistry. species in the equilibrium solution of a weak diprotic acid.

Define what strong and weak always mean in aqueous chemistry. species in the equilibrium solution of a weak diprotic acid. 1 of 14 After completing this chapter, you should, at a minimum, be able to do the following. This information can be found in my lecture notes for this and other chapters and also in your text. Correctly

More information

[H + ] =10 ph poh = -Log [OH - ] [OH - ]=10 poh

[H + ] =10 ph poh = -Log [OH - ] [OH - ]=10 poh Self Ionization of Water H 2 O H + + OH - Acids & Bases ph poh [H + ] [OH - ] Pure Water [H + ] = [OH - ], remember: [ ] means concentration 1 x 10 7 = 1 x 10 7 [H + ] > [OH - ], there is an acidic solution

More information

Self-Ionization of Water. Even pure water conducts some electricity. This is due to the fact that water self-ionizes:

Self-Ionization of Water. Even pure water conducts some electricity. This is due to the fact that water self-ionizes: 1 Self-Ionization of Water Even pure water conducts some electricity. This is due to the fact that water self-ionizes: Self ionization of water movie The equilibrium constant for this process is called

More information

Acids, Bases, and Salts

Acids, Bases, and Salts Acids, Bases, and Salts General Chemistry Ron Robertson I. Definitions The terms acid, base and salt are attempts to classify and organize reactions - these terms are used to model the behavior of species

More information

Chapter 16: Acid-Base Equilibria

Chapter 16: Acid-Base Equilibria Previous Chapter Table of Contents Next Chapter Chapter 16: Acid-Base Equilibria Section 16.1: The Common Ion Effect Here, we will discuss the acid-base properties of a solution with two solutes containing

More information

Chapter 16: Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Chapter 16: Acid-Base and Solubility Equilibria: Reactions in Soil and Water Chapter 16: Acid-Base and Solubility Equilibria: Reactions in Soil and Water Problems: 16.2-16.86 16.1 ACIDS AND BASES: THE BRØNSTED-LOWRY MODEL PROPERTIES OF ACIDS & BASES Acids produce hydrogen ions,

More information

Chapter 17 Practice Acids and Bases AP Chemistry The ph of 0.1-molar ammonia is approximately (A) 1 (B) 4 (C) 7 (D) 11 (E) 14

Chapter 17 Practice Acids and Bases AP Chemistry The ph of 0.1-molar ammonia is approximately (A) 1 (B) 4 (C) 7 (D) 11 (E) 14 Chapter 17 Practice Acids and Bases AP Chemistry 1984. The ph of 0.1-molar ammonia is approximately (A) 1 (B) 4 (C) 7 (D) 11 (E) 14 48. Which of the following ions is the strongest Lewis acid? (A) Na +

More information

Chapter 15 Acids- Bases. The Nature of Acids and Bases. Some Common Acid. Principles of Chemistry A Molecular Approach, 1 st Ed. Nivaldo J.

Chapter 15 Acids- Bases. The Nature of Acids and Bases. Some Common Acid. Principles of Chemistry A Molecular Approach, 1 st Ed. Nivaldo J. Chapter 15 -Acids and Bases Principles of Chemistry A Molecular Approach, 1 st Ed. Nivaldo J. Tro Dr. Azra Ghumman Memorial University of Newfoundland The Nature of Acids and Bases Properties of Acids:

More information

Arrhenius Theory of Acids

Arrhenius Theory of Acids Acids and Bases Chapter 17: 5, 6, 7, 9, 11, 13, 17, 18, 43, 67a-d, 71 Chapter 18: 5-9, 26, 27a-e, 32 Arrhenius Theory of Acids an acid-base reaction involves the reaction of hydrogen ions and hydroxide

More information

Arrhenius Model. Hydronium Ion. Chapter 13 Acids and Bases

Arrhenius Model. Hydronium Ion. Chapter 13 Acids and Bases Chapter 13 Acids and Bases What are Acids and Bases? Strong and Weak Acids and Bases Relative Strengths of Weak Acids Acidic, Basic, and Neutral Solutions The ph Scale Buffered Solutions 131 Copyright

More information

Unit 7: Acids & Bases

Unit 7: Acids & Bases Definitions of Acids & Bases Unit 7: Acids & Bases Chapter 16 Arrhenius Acid: Substance that, when dissolved in water, increases the concentration of hydrogen ions. Base: Substance that, when dissolved

More information

c) increase the temperature left right no change d) decrease the volume left right no change

c) increase the temperature left right no change d) decrease the volume left right no change 1. (8 pts) Consider the following reaction at equilibrium: N 2 O 4 (g) 2 NO 2 (g) The value of K is 0.90 at 120 o C and 3.2 at 150 o C. Predict how the equilibrium will shift by the following changes.

More information

5. The conjugate base of formic acid, HCOOH, is. A) OH B) CH 3 COO C) HCOO D) CO 2

5. The conjugate base of formic acid, HCOOH, is. A) OH B) CH 3 COO C) HCOO D) CO 2 1. A Br๘nsted acid is a(n). A) proton donor B) hydroxide ion donor C) proton acceptor D) electron donor 2. A Br๘nsted base. A) is a cation B) does not possess a lone pair of electrons C) possesses a lone

More information

CHAPTER 18 ACID-BASE EQUILIBRIA

CHAPTER 18 ACID-BASE EQUILIBRIA CHAPTER 18 ACID-BASE EQUILIBRIA Section 18.1: Acids and Bases in Water Water (H 2 O) the most important molecule on earth. Even in pure water, there are small amounts of ions from the equilibrium below

More information

BUFFERS. Buffers. Buffer Action 5/16/2011

BUFFERS. Buffers. Buffer Action 5/16/2011 BUFFERS Acids and Bases Buffers The purpose of a buffer is to maintain a relatively constant ph. Buffers are usually found in most biological systems because drastic changes in ph could cause major problems

More information

Answers and Solutions to Text Problems

Answers and Solutions to Text Problems Acids and Bases 10 Answers and Solutions to Text Problems 10.1 According to the Arrhenius theory: a. acids taste sour. b. acids neutralize bases. c. acids produce H 3 O + ions in water. d. potassium hydroxide

More information

Q.1 Classify the following according to Lewis theory and Brønsted-Lowry theory.

Q.1 Classify the following according to Lewis theory and Brønsted-Lowry theory. Acid-base A4 1 Acid-base theories ACIDS & BASES - IONIC EQUILIBRIA 1. LEWIS acid electron pair acceptor H, AlCl 3 base electron pair donor NH 3, H 2 O, C 2 H 5 OH, OH e.g. H 3 N: -> BF 3 > H 3 N BF 3 see

More information

AQUEOUS EQUILIBRIA. Salts Hydrolysis The Common-Ion Effect Buffer Solutions Acid-Base Titrations Solubility. Brown et al., Chapter 15,

AQUEOUS EQUILIBRIA. Salts Hydrolysis The Common-Ion Effect Buffer Solutions Acid-Base Titrations Solubility. Brown et al., Chapter 15, AQUEOUS EQUILIBRIA Salts Hydrolysis The Common-Ion Effect Buffer Solutions Acid-Base Titrations Solubility Brown et al., Chapter 15, 569-606 CHEM120 Lecture Series One : 2011/01 SALTS AND HYDROLYSIS Recall:

More information

Institute of Lifelong Learning, University of Delhi

Institute of Lifelong Learning, University of Delhi B.Sc (Prog.)IInd Year Paper No : CHPT 103 Chapter No and Name: 1, Ionic Equilibrium Author : Dr Mamta Sharma Department/College: Kirori Mal College, University of Delhi Reviewer: Dr. K. L. Kapoor, Associate

More information

Acid-Base Worksheet Answers are given at the end of all worksheets. Solve the problems before looking at the answers.

Acid-Base Worksheet Answers are given at the end of all worksheets. Solve the problems before looking at the answers. Acid-Base Worksheet Answers are given at the end of all worksheets. Solve the problems before looking at the answers. 1. What is ph of 0.0054 M HCl? 2. What is ph of 0.0054 M NaOH? 3. The concentration

More information

ph OF SOLUTIONS NH 3 (aq) + H 2 O(l) NH 4 + (aq) + OH & (aq) (3) base 1 acid 2 acid 1 base 2

ph OF SOLUTIONS NH 3 (aq) + H 2 O(l) NH 4 + (aq) + OH & (aq) (3) base 1 acid 2 acid 1 base 2 ph OF SOLUTIONS OBJECTIVES 1. To investigate the strengths of acids and bases 2. To examine the effect of concentration on the ph of a solution 3. To examine the effect of salt hydrolysis on ph 4. To determine

More information

Acids & Bases. Mr. Matthew Totaro Legacy High School AP Chemistry Pearson Education, Inc.

Acids & Bases. Mr. Matthew Totaro Legacy High School AP Chemistry Pearson Education, Inc. Acids & Bases Mr. Matthew Totaro Legacy High School AP Chemistry 2012 Pearson Education, Inc. Properties of Acids Sour taste React with active metals i.e., Al, Zn, Fe, but not Cu, Ag, or Au corrosive 2

More information

LESSON ASSIGNMENT. After completing this lesson, you should be able to: 9-2. Calculate buffers problems.

LESSON ASSIGNMENT. After completing this lesson, you should be able to: 9-2. Calculate buffers problems. LESSON ASSIGNMENT LESSON 9 ph and Buffers. TEXT ASSIGNMENT Paragraphs 9-1 through 9-23. LESSON OBJECTIVES After completing this lesson, you should be able to: 9-1. Calculate the ph and poh of a molar acid

More information

Acids and Bases Give the equation used to solve each problem and show all work. 5.76

Acids and Bases Give the equation used to solve each problem and show all work. 5.76 Acids and Bases Give the equation used to solve each problem and show all work. Name: Period: (1) Complete the following table. [H ] ph poh [OH ] 1.5x10 2 M acidic, basic, or neutral? 5.76 11.22.8x10 8

More information

Chapter 16 Acid and Bases. There is an equilibrium between these two ions in water or in any aqueous solution:

Chapter 16 Acid and Bases. There is an equilibrium between these two ions in water or in any aqueous solution: 1 I. Acidic and Basic water solutions: Chapter 16 Acid and Bases A. Dissociation of water The H + ion (or the H 3 O + ion) is characteristic of acidic water solutions. The OH - ion gives basic solutions

More information

Bases and Buffers. Table 8.3 Some Base Dissociation Constants at 25 C

Bases and Buffers. Table 8.3 Some Base Dissociation Constants at 25 C 8.3 Bases and Buffers Section Preview/ Specific Epectations In this section, you will solve problems that involve the base dissociation constant, K b describe the properties and components of a buffer

More information

Buffers (2).notebook. March 14, 2016

Buffers (2).notebook. March 14, 2016 In this activity we will develop principles involved in making a buffer solution and then determine how a buffer minimizes changes in the ph upon addition of strong acid or base. Buffers consist of a weak

More information

CHEM N-8 November 2003

CHEM N-8 November 2003 CHEM1909 2003-N-8 November 2003 The H 2 PO 4 and HPO 4 2 ions play a major role in maintaining the intracellular ph balance. Write balanced equations to show how a solution containing these ions can act

More information

Study Guide for Module 15A Acids & Bases III

Study Guide for Module 15A Acids & Bases III Chemistry 1020, Module 15A Name Study Guide for Module 15A Acids & Bases III Reading Assignment: Sections 4.8, 14.7, 15.1, 15.2, 15.3, 15.4, 15.5 and 15.8 in Chemistry, 6th Edition by Zumdahl. Guide for

More information

Chapter 15: Acids and Bases I. Chem 102 Dr. Curtis

Chapter 15: Acids and Bases I. Chem 102 Dr. Curtis Chapter 15: Acids and Bases I Chem 102 Dr. Curtis Acids and Bases Acids Sour taste vinegar Dissolve many metals Ability to neutralize bases Strong or Weak Bases Bitter taste caffeine, poisons from plants

More information

QUESTION (2012:3) (a) (i) Complete the table below showing the conjugate acids and bases. CO 3 H 2 O OH HCN CN -

QUESTION (2012:3) (a) (i) Complete the table below showing the conjugate acids and bases. CO 3 H 2 O OH HCN CN - QUESTION (2012:3) (i) Complete the table below showing the conjugate acids and bases. Conjugate acid Conjugate base - HCO 3 2 CO 3 H 2 O OH HCN CN - (ii) HPO 4 2 (aq) Write equations for the reactions

More information

AMHS AP Chemistry Multiple Choice questions

AMHS AP Chemistry Multiple Choice questions 1 Aqueous Equilibria: Buffers & Titrations AMHS AP Chemistry Multiple Choice questions Name Common-Ion Effect 1) The ph of a solution that contains 0.818 M acetic acid (K a = 1.77x10-5 ) and 0.172 M sodium

More information

AP*Chemistry The Chemistry of Acids and Bases

AP*Chemistry The Chemistry of Acids and Bases AP*Chemistry The Chemistry of Acids and Bases "ACID"--Latin word acidus, meaning sour. (lemon) "ALKALI"--Arabic word for the ashes that come from burning certain plants; water solutions feel slippery and

More information

Chapter 15 - Applications of Aqueous Equilibrium

Chapter 15 - Applications of Aqueous Equilibrium Chapter 15 - Applications of Aqueous Equilibrium AP Chemistry Common Ion Effect COMMON ION EFFECT - Calculate [H+] for a 1.0 M HF solution (K a = 7.2 x 10-4 ). Then calculate % ionization for this solution.

More information

CHAPTER 17: Advanced Acid-Base Equilibria

CHAPTER 17: Advanced Acid-Base Equilibria CHAPTER 17: Advanced Acid-Base Equilibria Chapter In Context We will now expand the introductory coverage of acid-base equilibria in the previous chapter and explore the chemistry of more complicated aqueous

More information

Chapter 16 Acid-Base Equilibria

Chapter 16 Acid-Base Equilibria Chapter 16 AcidBase Equilibria Acids and bases are found in many common substances and are important in life processes. Group Work: Make a list of some common acids and bases. How do we know which is which?

More information