Ch 15, Applications of Aqueous Equilibria

Size: px
Start display at page:

Download "Ch 15, Applications of Aqueous Equilibria"

Transcription

1 Ch 15, Applications of Aqueous Equilibria We will focus on 3 areas: 1) titrations, 2) buffers (incl. the Henderson-Hasselbalch Transformation), 3) solubility equilibria. I. Neutralization Reactions A. Strong acid-strong base 1. Let s start by looking at an example: HCl(aq) + NaOH(aq) W H 2 O(l) + NaCl(aq) 2. Can you write a net ionic equation for the above? + W 3. Will the above rxn have mostly products or reactants present at equilibrium? Logic? B. Weak acid-strong base 1. Again, let s start by looking at an example: CH 3 COOH(aq) + NaOH(aq) W H 2 O(l) + CH 3 COONa(aq) Is Na + doing anything interesting? No, so leave it out! Remember your previous experience w/ spectator ions? CH 3 COOH(aq) + OH! (aq) W H 2 O(l) + CH 3 COO! (aq) How far will this proceed toward products? 1

2 We can define a neutralization constant, K n, as: [CH 3 COO K! ] n = [CH3 COOH] [OH! ] 2. Is there any way we can get a value for K n without going into the lab and measuring it? Try finding 2 equations that sum to the one above: CH 3 COOH + H 2 O W H 3 O + + CH 3 COO! K a = 1.8 x 10!5 H 3 O + + OH! W 2 H 2 O 1/ K w = 1.0 x CH 3 COOH + OH! W H 2 O + CH 3 COO! K n = K a (1/K w ) K n = 1.8 x Therefore, the rxn. goes essentially to completion. C. Strong acid-weak base. Same as B. above. D. Weak acid-weak base 1. In B, we could ignore Na + because it has essentially no acid-base properties. In this of problem, neither component is weak enough to ignore. 2. Look at the rxn. of acetic acid with ammonia: CH 3 COOH(aq) + NH 3 (aq) W NH 4 + (aq) + CH 3 COO! (aq) 2

3 What rxns. will sum to give us that rxn.? + W + K a = + W + K b = + W = CH 3 COOH(aq) + NH 3 (aq) W NH 4 + (aq) + CH 3 COO! (aq) K n = K a x K b x K n = 3. Will the system contain mostly products or reactants at equilibrium? 4. Perform a similar analysis with HCN (a weaker acid) as the acid instead of CH 3 COOH on your own. Try prob (a & d?), p II. The Common Ion Effect (build up to buffers) A. In Chapter 14 we confined our discussion to solns. of pure acid or base. We now consider in more detail what happens when you look at mixed systems. 3

4 1. Consider mixing acetic acid and sodium acetate: CH 3 COOH(l) + CH 3 COONa(s) W Na + (aq) + H 3 O + (aq) + CH 3 COO! (aq) Can we calculate [CH 3 COOH], [H 3 O + ], & [CH 3 COO! ] at equilibrium? ([Na + ] ususally not of interest.) 2. Use the same approach we developed in Chapter 14 (Fig. 14.7). Main difference: [CH 3 COO! ] initial 0. a) Step #1, Identify reactive (interesting) species: CH 3 COOH Na + H 2 O CH 3 COO! acid inert acid/base base b) Step #2-3, Identify principle reaction: CH 3 COOH + H 2 O W H 3 O + + CH 3 COO! K a = 1.8 x 10!5 c) Step #4, Set up the table. d) Step #5, Substitute values into the K a expression e) Steps remaining, do the algebra. (See Fig. 15.2) Try Key Concept Prob. 15.5, p Do Prob

5 III. Buffer Solutions A. These are tremendously important in your body. B. A buffered solution resists ph changes (relative to a non-buffered solution) upon addition of acid or base. C. How do we make a buffer? 1. Mix a weak acid with its conjugate base. 2. Mix a weak base with its conjugate acid. D. How does a buffer work? 1. Think back to the buffer we looked at in Prob a) What happens if you add a OH! to the buffer? HCN + OH! ÿ H 2 O + CN! b) What happens if you add a H 3 O + to the buffer? CN! + H 3 O + ÿ H 2 O + HCN 2. Buffer capacity. There is a limit to how much acid or base the buffer can absorb. a) The amount of acid that can be absorbed is related to how much basic component (CN! above) of the buffer is present. b) The amount of base that can be absorbed is related to how much acidic component (HCN above) of the buffer is present. 5

6 E. Where (on the ph scale) does a buffer work? 1. Recall the K a expression: [H 3 O K + ] [A! ] a = [HA] 2. This can be rearranged to obtain: K a [HA] [H 3 O + ] = [A! ] 3. This tells us: a) The [H 3 O + ] (and therefore ph) is determined by the ratio of acid and conjugate base. b) The ph of effective buffering depends on K a. Do Key Concept Prob. 15.6, p IV. The Henderson-Hasselbalch Transformation Some concepts are much more clear if you look at them from a specific point of view. H-H Transformation makes some aspects of buffers more clear. This is a transformation because you are just rearranging the K a expression. 6

7 A. Derivation. Let s start with the K a expression: Distributive law to get: K a = [H 3 O + ] [A! ] [HA] [A! ] K a = [H 3 O + ] x [HA] Take log of both sides: log K a = log [H 3 O + ] + log ([A! ]/[HA]) Rearrange:!log [H 3 O + ] =!log K a + log ([A! ]/[HA]) Finally, use definitions: ph = pk a + log ([A! ]/[HA]) This is the H-H equation. (Note: pk a = ) B. What use is this, anyway? Let s see what happens when we mix equimolar quantities of buffer components (HA and A! ). ph = pk a + log (x/x) Because log 1 = 0, ph = pk a 1. Buffers are most effective buffering against both H + & OH! addition when buffer ph = pk a of that HA. 2. Look at the [base] ' [acid] ratios on p Try Prob , p

8 4. Look at the Normal Values section of: a) Do any of: ph'paco 2 'PaO 2 'SaO 2 ' HCO 3! relate to variables in the H-H transformation? Which relate to acid-base chemistry? ph ph = pk a + log([a! ]'[HA]) P a CO 2 P a O 2 SaO 2 HCO 3! b) Is HCO 3! acting like an acid or a base? See pk a values above, think of CO 2 leaving the body. V. ph Titration Curves A. Titration: quantitative analysis method in chemistry. Based on chemical rxns. To do one, you need to know: 1. The stoichiometry for the reaction. 2. The concentration of the known component. 3. The volume of known component added. B. If you know these things, you can calculate the quantity of unknown present in a sample. C. You may also get pk a information from a titration. 8

9 VI. Strong Acid-Strong Base Titrations A. You get only quantitative information with these. B. The interesting component of a strong acid is H 3 O +, for a strong base it is OH!. 100% H 3 O + (aq) + OH! (aq) ÿ 2H 2 O(l) 1. See Fig for titration of HCl with known NaOH. 2. Shape of curve. Note equivalence point at ph = 7.0. VII. Weak Acid-Strong Base Titrations A. You get quantitative & K a information with these. B. Again, a weak acid reaction with a strong base goes to completion: 100% HA(aq) + OH! (aq) ÿ H 2 O(l) + A! 1. See Fig for titration of CH 3 COOH with NaOH. 2. Note equivalence point at ph 7.0. (Indicator?) 3. Shape (vs. ph location) of the curve for different weak acids? See Fig. 15.8, p This figure helps re. logic of buffers. C. If you dissolve H 2 SO 4 in water so [H 2 SO 4 ] total = 0.5 M, can you predict [H 2 SO 4 ],[HSO 4! ], [SO 4 2! ], & [H 3 O + ] =? 9

10 VIII. Weak Base-Strong Acid Titrations (See VII) IX. Polyprotic Acid-Strong Base Titrations A. Analogous to VII, above. See Fig , p B. Try Prob , p. 618 on your own. X. Solubility Equilibria A. Examples of biological solubility problems: 1. tooth decay 2. Atherosclerosis 3. Kidney stones B. Consider the equilibrium: CaF 2 (s) WCa 2+ (aq) + 2 F! (aq) C. Can you write an equilibrium constant expression for this equilibrium? K sp = 1. K sp is called the solubility product. 2. Different salts have different (sometimes very different) K sp values. Qual scheme? Try Prob c), p

11 XI. Measuring K sp, Calculating Solubility from K sp A. Two ways to approach this problem: 1. Add increasing concentrations of components of interest until you see a ppt. (Example?) 2. Form a saturated soln. and then measure concentrations of ions in soln. B. We will examine some of the reasons for differences in K sp values between different salts later. Try Prob , p XII. Factors That Affect Solubility A. The common-ion effect What happens if you add MgCl 2 to a soln. of MgF 2 (aq)? See Prob , p B. ph Effects Look for a component that reacts with H 3 O + or OH!. Review pp on your own. This will be particularly helpful in your understanding of the qual scheme. 11

Titrations. Acid-Base Indicators and Titration Curves. Shapes of Titration Curves. A titration curve is a graphical history of a titration

Titrations. Acid-Base Indicators and Titration Curves. Shapes of Titration Curves. A titration curve is a graphical history of a titration Acid-Base Indicators and Titration Curves Titrations In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration until the chemical

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 9 Lecture Notes: Acids, Bases and Equilibrium

Chapter 9 Lecture Notes: Acids, Bases and Equilibrium Chapter 9 Lecture Notes: Acids, Bases and Equilibrium Educational Goals 1. Given a chemical equation, write the law of mass action. 2. Given the equilibrium constant (K eq ) for a reaction, predict whether

More information

ph: Measurement and Uses

ph: Measurement and Uses ph: Measurement and Uses One of the most important properties of aqueous solutions is the concentration of hydrogen ion. The concentration of H + (or H 3 O + ) affects the solubility of inorganic and organic

More information

Chapter 16: Acid-Base Equilibria

Chapter 16: Acid-Base Equilibria Chapter 16: Acid-Base Equilibria In the 1 st half of this chapter we will focus on the equilibria that exist in aqueous solutions containing: weak acids polyprotic acids weak bases salts use equilibrium

More information

Chemical equilibria Buffer solutions

Chemical equilibria Buffer solutions Chemical equilibria Buffer solutions Definition The buffer solutions have the ability to resist changes in ph when smaller amounts of acid or base is added. Importance They are applied in the chemical

More information

Equilibrium, Acids and Bases Unit Summary:

Equilibrium, Acids and Bases Unit Summary: Equilibrium, Acids and Bases Unit Summary: Prerequisite Skills and Knowledge Understand concepts of concentration, solubility, saturation point, pressure, density, viscosity, flow rate, and temperature

More information

CH302 Exam 4 Practice Problems (buffers, titrations, Ksp)

CH302 Exam 4 Practice Problems (buffers, titrations, Ksp) CH302 Exam 4 Practice Problems (buffers, titrations, Ksp) 1 Equilibrium Constants The following equilibrium constants will be useful for some of the problems. Substance Constant Substance Constant HCO

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

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

Chapter 21 Buffers and the titration of Acids and Bases Shuffle order make 21-3 last!

Chapter 21 Buffers and the titration of Acids and Bases Shuffle order make 21-3 last! Chapter 21 Buffers and the titration of Acids and Bases Shuffle order make 213 last! 211 The HendersonHasselbalch Equation What happens when you mix an acid and its own conjugate base? Using an acetic

More information

Name period Unit 9: acid/base equilibrium

Name period Unit 9: acid/base equilibrium Name period Unit 9: acid/base equilibrium 1. What is the difference between the Arrhenius and the BronstedLowry definition of an acid? Arrhenious acids give H + in water BronstedLowry acids are proton

More information

Titration curves. Strong Acid-Strong Base Titrations

Titration curves. Strong Acid-Strong Base Titrations Titration curves A titration is a procedure for carrying out a chemical reaction between two solutions by the controlled addition from a buret of one solution (the titrant) to the other, allowing measurements

More information

Acids and Bases. Basic Definitions & Concepts

Acids and Bases. Basic Definitions & Concepts Acids and Bases CHEM 102! T. Hughbanks! Basic Definitions & Concepts Most basic concepts are given clearly in your text - these notes will only list these as topics discussed, so there will be less detail.!

More information

An acid is a substance that produces H + (H 3 O + ) Ions in aqueous solution. A base is a substance that produces OH - ions in aqueous solution.

An acid is a substance that produces H + (H 3 O + ) Ions in aqueous solution. A base is a substance that produces OH - ions in aqueous solution. Chapter 8 Acids and Bases Definitions Arrhenius definitions: An acid is a substance that produces H + (H 3 O + ) Ions in aqueous solution. A base is a substance that produces OH - ions in aqueous solution.

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

Chem101: General Chemistry Lecture 9 Acids and Bases

Chem101: General Chemistry Lecture 9 Acids and Bases : General Chemistry Lecture 9 Acids and Bases I. Introduction A. In chemistry, and particularly biochemistry, water is the most common solvent 1. In studying acids and bases we are going to see that water

More information

Equilibria Involving Acids & Bases

Equilibria Involving Acids & Bases Week 9 Equilibria Involving Acids & Bases Acidic and basic solutions Self-ionisation of water Through reaction with itself: The concentration of water in aqueous solutions is virtually constant at about

More information

Chapter 17. The best buffer choice for ph 7 is NaH 2 PO 4 /Na 2 HPO 4. 19)

Chapter 17. The best buffer choice for ph 7 is NaH 2 PO 4 /Na 2 HPO 4. 19) Chapter 17 2) a) HCl and CH 3 COOH are both acids. A buffer must have an acid/base conjugate pair. b) NaH 2 PO 4 and Na 2 HPO 4 are an acid/base conjugate pair. They will make an excellent buffer. c) H

More information

Titration Curve of a Weak Acid

Titration Curve of a Weak Acid Titration Curve of a Weak Acid Amina Khalifa El-Ashmawy, Ph.D. Collin College Department of Chemistry Introduction: Titration is an analytical process whereby two reactant solutions are carefully reacted

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

14-Jul-12 Chemsheets A

14-Jul-12 Chemsheets A www.chemsheets.co.uk 14-Jul-12 Chemsheets A2 009 1 BRONSTED-LOWRY ACIDS & BASES Bronsted-Lowry acid = proton donor (H + = proton) Bronsted-Lowry base = proton acceptor (H + = proton) Bronsted-Lowry acid-base

More information

ph Measurement and its Applications

ph Measurement and its Applications ph Measurement and its Applications Objectives: To measure the ph of various solutions using ph indicators and meter. To determine the value of K a for an unknown acid. To perform a ph titration (OPTIONAL,

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

Worksheet 23 Strong Acid/Strong Base Titrations

Worksheet 23 Strong Acid/Strong Base Titrations Worksheet 2 Strong Acid/Strong Base Titrations A. Initial ph This is always determined based solely on the initial concentration of the acid or base being titrated. Every mole of acid or base will produce

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

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

Acid/Base Definition. Acid/Base Reactions. Major vs. Minor Species. Terms/Items you Need to Know. you need to memorize these!!

Acid/Base Definition. Acid/Base Reactions. Major vs. Minor Species. Terms/Items you Need to Know. you need to memorize these!! Acid/Base Reactions some covalent compounds have weakly bound H atoms and can lose them to water (acids) some compounds produce OH in water solutions when they dissolve (bases) acid/base reaction are very

More information

Copyright 2009 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

Copyright 2009 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Sample Exercise 17.1 Calculating the ph When a Common Ion is Involved What is the ph of a solution made by adding 0.30 mol of acetic acid and 0.30 mol of sodium acetate to enough water to make 1.0 L of

More information

Common Ion Effects. CH 3 CO 2 (aq) + Na + (aq)

Common Ion Effects. CH 3 CO 2 (aq) + Na + (aq) Common Ion Effects If two reactions both involve the same ion, then one reaction can effect the equilibrium position of the other reaction. The ion that appears in both reactions is the common ion. Buffers

More information

Chapter 7 Mixtures of Acids and Bases

Chapter 7 Mixtures of Acids and Bases Chapter 7 Mixtures of Acids and Bases Introduction In Chapter 6, we examined the equilibrium concentrations in solutions of acids and solutions of bases. In this chapter, we continue our discussion of

More information

Acids and Bases. When an acid loses a proton, the resulting species is its conjugate base. For example, NH 3 + H +

Acids and Bases. When an acid loses a proton, the resulting species is its conjugate base. For example, NH 3 + H + Acids and Bases Definitions An acid is a proton donor, e.g. HCl. For example, consider the reaction between HCl and H 2 O. HCl + H 2 O H 3 O + + Cl - Acid In this reaction, HCl donates a proton to H 2

More information

CHEM 102: Sample Test 5

CHEM 102: Sample Test 5 CHEM 102: Sample Test 5 CHAPTER 17 1. When H 2 SO 4 is dissolved in water, which species would be found in the water at equilibrium in measurable amounts? a. H 2 SO 4 b. H 3 SO + 4 c. HSO 4 d. SO 2 4 e.

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

If we write these equations in ionic form, in each case the net ionic equation is the same; H 3 O + (aq) + OH - (aq) H 2H 2 O(l)

If we write these equations in ionic form, in each case the net ionic equation is the same; H 3 O + (aq) + OH - (aq) H 2H 2 O(l) CHEM 1105 ACIDS AND BASES 1. Early Definitions Taste: Effect on Indicators: Neutralization: acids - sour; bases - bitter acids turn blue litmus red; bases turn red litmus blue phenolphthalein is colourless

More information

Chapter 10 Acid-Base titrations Problems 1, 2, 5, 7, 13, 16, 18, 21, 25

Chapter 10 Acid-Base titrations Problems 1, 2, 5, 7, 13, 16, 18, 21, 25 Chapter 10 AcidBase titrations Problems 1, 2, 5, 7, 13, 16, 18, 21, 25 Up to now we have focused on calculations of ph or concentration at a few distinct points. In this chapter we will talk about titration

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 2816 1 Acid-base theories ACIDS & BASES - IONIC EQUILIBRIA 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

More information

Equilibrium Constants The following equilibrium constants will be useful for some of the problems.

Equilibrium Constants The following equilibrium constants will be useful for some of the problems. 1 CH302 Exam 4 Practice Problems (buffers, titrations, Ksp) Equilibrium Constants The following equilibrium constants will be useful for some of the problems. Substance Constant Substance Constant HCO

More information

Acid-Base (Proton-Transfer) Reactions

Acid-Base (Proton-Transfer) Reactions Acid-Base (Proton-Transfer) Reactions Chapter 17 An example of equilibrium: Acid base chemistry What are acids and bases? Every day descriptions Chemical description of acidic and basic solutions by Arrhenius

More information

Acids and Bases. Chapter 16

Acids and Bases. Chapter 16 Acids and Bases Chapter 16 The Arrhenius Model An acid is any substance that produces hydrogen ions, H +, in an aqueous solution. Example: when hydrogen chloride gas is dissolved in water, the following

More information

CHAPTER 9. ANS: a. ANS: d. ANS: c. ANS: a. ANS: c

CHAPTER 9. ANS: a. ANS: d. ANS: c. ANS: a. ANS: c CHAPTER 9 1. Which one of the following is the acid in vinegar? a. acetic acid b. citric acid c. muriatic acid d. ascorbic acid 2. Which is a basic or alkaline substance? a. gastric fluid b. black coffee

More information

Chapter 4: Reactions in Aqueous Solution (Sections )

Chapter 4: Reactions in Aqueous Solution (Sections ) Chapter 4: Reactions in Aqueous Solution (Sections 4.1-4.12) Chapter Goals Be able to: Classify substances as electrolytes or nonelectrolytes. Write molecular, ionic, and net ionic equations for precipitation,

More information

Ch. 7 - Acids and Bases cont. Determining Acid Strength. Determining Acid Strength

Ch. 7 - Acids and Bases cont. Determining Acid Strength. Determining Acid Strength Ch. 7 - Acids and Bases cont. Last Week Arrhenius vs. Bronsted-Lowry Acids and Bases Conjugate Acid-Base Pairs Water: Acid or Base ph and Related Simple Calculations Today Acid Strength More ph Calculations

More information

Note: (H 3 O + = hydronium ion = H + = proton) Example: HS - + H 2 O H 3 O + + S 2-

Note: (H 3 O + = hydronium ion = H + = proton) Example: HS - + H 2 O H 3 O + + S 2- AcidBase Chemistry Arrhenius acid: Substance that dissolves in water and provides H + ions Arrhenius base: Substance that dissolves in water and provides OH ions Examples: HCl H + and Cl Acid NaOH Na +

More information

Strong Acids (Know These) Announcements & Agenda (02/23/07) Strengths of Acids/Bases - Ionization. Last Time: Last Time: nsted-lowry Acids & Bases

Strong Acids (Know These) Announcements & Agenda (02/23/07) Strengths of Acids/Bases - Ionization. Last Time: Last Time: nsted-lowry Acids & Bases Announcements & Agenda (0//07) You should be reading Ch 0 this weekend! Quiz Today! Open Review Sessions @ pm on Wed. Low attendance this week Last Time: Bronsted nsted-lowry Acids & Bases acids donate

More information

Similarities The ph of each of these solutions is the same; that is, the [H + ] is the same in both beakers (go ahead and count).

Similarities The ph of each of these solutions is the same; that is, the [H + ] is the same in both beakers (go ahead and count). Compare 1 L of acetate buffer solution (0.50 mol of acetic acid and 0.50 mol sodium acetate) to 1 L of HCl solution AcO - AcO - H+ Cl - AcO - AcO - Cl - Cl - AcO - Cl - Cl - Cl - Cl - AcO - AcO - AcO -

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

2. Write a balanced chemical equation which corresponds to the following equilibrium constant expression. 1/2 3/ 2

2. Write a balanced chemical equation which corresponds to the following equilibrium constant expression. 1/2 3/ 2 Practice Problems for Chem. 1B Exam 1 F2011 These represent the concepts covered for exam 1. There may be some additional net ionic equations from chem. 1A. This is not the exact exam! Sections 16.1-16.3

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

Chemical Equations. Chemical Equations. Chemical reactions describe processes involving chemical change

Chemical Equations. Chemical Equations. Chemical reactions describe processes involving chemical change Chemical Reactions Chemical Equations Chemical reactions describe processes involving chemical change The chemical change involves rearranging matter Converting one or more pure substances into new pure

More information

V. POLYPROTIC ACID IONIZATION. NOTICE: K a1 > K a2 > K a3 EQUILIBRIUM PART 2. A. Polyprotic acids are acids with two or more acidic hydrogens.

V. POLYPROTIC ACID IONIZATION. NOTICE: K a1 > K a2 > K a3 EQUILIBRIUM PART 2. A. Polyprotic acids are acids with two or more acidic hydrogens. EQUILIBRIUM PART 2 V. POLYPROTIC ACID IONIZATION A. Polyprotic acids are acids with two or more acidic hydrogens. monoprotic: HC 2 H 3 O 2, HCN, HNO 2, HNO 3 diprotic: H 2 SO 4, H 2 SO 3, H 2 S triprotic:

More information

Acids, Bases, Salts, and Buffers

Acids, Bases, Salts, and Buffers Acids, Bases, Salts, and Buffers GOAL AND OVERVIEW Hydrolysis of salts will be used to study the acid-base properties of dissolved ions in aqueous solutions. The approximate ph of these solutions will

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

7 Investigation of Buffer Systems

7 Investigation of Buffer Systems 7 Investigation of Buffer Systems Name: Date: Section: Objectives Reinforce concepts of buffer, buffer range and buffer capacity Learn how to prepare acid-base buffers Learn how to calculate the of a buffer

More information

Types of Reactions. What are Acids &Bases? Chapter 15. Acids & Bases. Definition? a) Arrhenius. b) Bronsted-Lowry. c) Lewis

Types of Reactions. What are Acids &Bases? Chapter 15. Acids & Bases. Definition? a) Arrhenius. b) Bronsted-Lowry. c) Lewis Chapter 15. Acids & Bases Acid/Base Definitions Types of Acids/bases Polyprotic Acids The Ion Product for Water The ph and Other p Scales Aqueous Solutions of Acids and Bases Hydrolysis The Common Ion

More information

SECTION 14 CHEMICAL EQUILIBRIUM

SECTION 14 CHEMICAL EQUILIBRIUM 1-1 SECTION 1 CHEMICAL EQUILIBRIUM Many chemical reactions do not go to completion. That is to say when the reactants are mixed and the chemical reaction proceeds it only goes to a certain extent, and

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

ACID-BASE REACTIONS/ THE PH CONCEPT.

ACID-BASE REACTIONS/ THE PH CONCEPT. Dr Mike Lyons School of Chemistry Trinity College Dublin. melyons@tcd.ie ACID-BASE REACTIONS/ THE PH CONCEPT. Chemistry Preliminary Course 2011 1 Lecture topics. 2 lectures dealing with some core chemistry

More information

Notes: Acids and Bases

Notes: Acids and Bases Name Chemistry Pre-AP Notes: Acids and Bases Period I. Describing Acids and Bases A. Properties of Acids taste ph 7 Acids change color of an (e.g. blue litmus paper turns in the presence of an acid) React

More information

TOPIC 11: Acids and Bases

TOPIC 11: Acids and Bases TOPIC 11: Acids and Bases ELECTROLYTES are substances that when dissolves in water conduct electricity. They conduct electricity because they will break apart into Ex. NaCl(s)! Na + (aq) + Cl - (aq), and

More information

We remember that molarity (M) times volume (V) is equal to moles so this relationship is the definition of the equivalence point.

We remember that molarity (M) times volume (V) is equal to moles so this relationship is the definition of the equivalence point. Titrations Titration - a titration is defined as the determination of the amount of an unknown reagent (analyte) through the use of a known amount of another reagent (titrant) in an essentially irreversible

More information

Lecture 6. Classes of Chemical Reactions

Lecture 6. Classes of Chemical Reactions Lecture 6 Classes of Chemical Reactions Lecture 6 Outline 6.1 The Role of Water as a Solvent 6.2 Precipitation Reactions 6.3 Acid-Base Reactions 1 Electron distribution in molecules of H 2 and H 2 O The

More information

3. Which of the following describes a conjugate acid-base pair for the following equilibrium? CN - (aq) + CH 3 NH 3 + (aq) H 2 CO 3 (aq) + H 2 O (l)

3. Which of the following describes a conjugate acid-base pair for the following equilibrium? CN - (aq) + CH 3 NH 3 + (aq) H 2 CO 3 (aq) + H 2 O (l) Acids, Bases & Redox 1 Practice Problems for Assignment 8 1. A substance which produces OH ions in solution is a definition for which of the following? (a) an Arrhenius acid (b) an Arrhenius base (c) a

More information

ph. Weak acids. A. Introduction

ph. Weak acids. A. Introduction ph. Weak acids. A. Introduction... 1 B. Weak acids: overview... 1 C. Weak acids: an example; finding K a... 2 D. Given K a, calculate ph... 3 E. A variety of weak acids... 5 F. So where do strong acids

More information

Volumetric Analysis. Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115

Volumetric Analysis. Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115 Volumetric Analysis Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115 Experimental Aims To prepare and standardize (determine concentration) a NaOH solution Using your standardized NaOH calculate

More information

stoichiometry = the numerical relationships between chemical amounts in a reaction.

stoichiometry = the numerical relationships between chemical amounts in a reaction. 1 REACTIONS AND YIELD ANSWERS stoichiometry = the numerical relationships between chemical amounts in a reaction. 2C 8 H 18 (l) + 25O 2 16CO 2 (g) + 18H 2 O(g) From the equation, 16 moles of CO 2 (a greenhouse

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

Chemistry 201. Practical aspects of buffers. NC State University. Lecture 15

Chemistry 201. Practical aspects of buffers. NC State University. Lecture 15 Chemistry 201 Lecture 15 Practical aspects of buffers NC State University The everyday ph scale To review what ph means in practice, we consider the ph of everyday substances that we know from experience.

More information

Chemistry 106 Fall 2007 Exam 3 1. Which one of the following salts will form a neutral solution on dissolving in water?

Chemistry 106 Fall 2007 Exam 3 1. Which one of the following salts will form a neutral solution on dissolving in water? 1. Which one of the following salts will form a neutral solution on dissolving in water? A. NaCN B. NH 4 NO 3 C. NaCl D. KNO 2 E. FeCl 3 2. Which one of the following is a buffer solution? A. 0.10 M KCN

More information

CHM1 Review for Exam 12

CHM1 Review for Exam 12 Topics Solutions 1. Arrhenius Acids and bases a. An acid increases the H + concentration in b. A base increases the OH - concentration in 2. Strong acids and bases completely dissociate 3. Weak acids and

More information

Topic 5. Acid and Bases

Topic 5. Acid and Bases Topic 5 5-1 Acid and Bases Acid and Bases 5-2 There are a number definitions for aicd and bases, depending on what is convenient to use in a particular situation: Arrhenius and Ostwald: Theory of electrolyte

More information

1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11

1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11 SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436

More information

3 The Preparation of Buffers at Desired ph

3 The Preparation of Buffers at Desired ph 3 The Preparation of Buffers at Desired ph Objectives: To become familiar with operating a ph meter, and to learn how to use the Henderson-Hasselbalch equation to make buffer solutions at a desired ph

More information

Write the acid-base equilibria connecting all components in the aqueous solution. Now list all of the species present.

Write the acid-base equilibria connecting all components in the aqueous solution. Now list all of the species present. Chapter 16 Acids and Bases Concept Check 16.1 Chemists in the seventeenth century discovered that the substance that gives red ants their irritating bite is an acid with the formula HCHO 2. They called

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

A strong acid and the salt of its conjugate base don't make a good buffer. Why? (aq) + OH - (aq)

A strong acid and the salt of its conjugate base don't make a good buffer. Why? (aq) + OH - (aq) 5.111 Lecture Summary #23 cid/base Equilibrium Continued From Friday s handout Topic: Titrations 23.1 cid buffer action: The weak acid,, transfers protons to O ions supplied by strong base. The conjugate

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

Ch 8.5 Solution Concentration Units % (m/m or w/w) = mass of solute x 100 total mass of solution mass of solution = mass solute + mass solvent

Ch 8.5 Solution Concentration Units % (m/m or w/w) = mass of solute x 100 total mass of solution mass of solution = mass solute + mass solvent 1 Ch 8.5 Solution Concentration Units % (m/m or w/w) = mass of solute x 100 total mass of solution mass of solution = mass solute + mass solvent % (v/v) = volume of solute x 100 volume of solution filled

More information

Factors that Affect the Rate of Dissolving and Solubility

Factors that Affect the Rate of Dissolving and Solubility Dissolving Factors that Affect the Rate of Dissolving and Solubility One very important property of a solution is the rate of, or how quickly a solute dissolves in a solvent. When dissolving occurs, there

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

Chapter 4 Notes - Types of Chemical Reactions and Solution Chemistry

Chapter 4 Notes - Types of Chemical Reactions and Solution Chemistry AP Chemistry A. Allan Chapter 4 Notes - Types of Chemical Reactions and Solution Chemistry 4.1 Water, the Common Solvent A. Structure of water 1. Oxygen's electronegativity is high (3.5) and hydrogen's

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

Experiment # 6 Determining the percent composition of a mixture by acid-base

Experiment # 6 Determining the percent composition of a mixture by acid-base Experiment # 6 Determining the percent composition of a mixture by acid-base Objective Determine the percent composition of a mixture of sodium carbonate (Na 2 CO 3 ), sodium bicarbonate (NaHCO 3 ) and

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

UNIT (6) ACIDS AND BASES

UNIT (6) ACIDS AND BASES UNIT (6) ACIDS AND BASES 6.1 Arrhenius Definition of Acids and Bases Definitions for acids and bases were proposed by the Swedish chemist Savante Arrhenius in 1884. Acids were defined as compounds that

More information

Answer the following questions on notebook paper, to be collected and graded for correctness.

Answer the following questions on notebook paper, to be collected and graded for correctness. nswer the following questions on notebook paper, to be collected and graded for correctness. 1. Name the following binary acids: a. HCl hydrochloric acid b. HF hydrofluoric acid c. H 2 S hydrosulfuric

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

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. A.P. Chemistry Practice Test: Ch. 14, Acids and Bases Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The conjugate base of HSO4 - is A) H2SO4

More information

Experiment 6 Titration II Acid Dissociation Constant

Experiment 6 Titration II Acid Dissociation Constant 6-1 Experiment 6 Titration II Acid Dissociation Constant Introduction: An acid/base titration can be monitored with an indicator or with a ph meter. In either case, the goal is to determine the equivalence

More information

Test 12: Review questions

Test 12: Review questions Name: Wednesday, April 16, 2008 Test 12: Review questions 1. Which reaction represents the process of neutralization? 1. Mg(s) + 2HCl(aq) MgCl 2(aq) + H 2(g) 2. HCl(aq) + KOH(aq) KCl(aq) + H2O(l) 3. Pb(NO

More information

Acid-Base Titrations. Setup for a Typical Titration. Titration 1

Acid-Base Titrations. Setup for a Typical Titration. Titration 1 Titration 1 Acid-Base Titrations Molarities of acidic and basic solutions can be used to convert back and forth between moles of solutes and volumes of their solutions, but how are the molarities of these

More information

Topic 18 Acids and Bases. 18.1 Exercises

Topic 18 Acids and Bases. 18.1 Exercises Topic 18 Acids and Bases 18.1 Exercises 1. Define: (a) ph The negative log of the hydrogen ion concentration in a solution. i.e. ph = log[h 3 O + ] (b) poh The negative log of hydroxide ion concentration

More information

16. What is the H 3 O + concentration of a solution that has an OH concentration of 1 10 3 M? 1) 1 10 4 M 3) 1 10 11 M

16. What is the H 3 O + concentration of a solution that has an OH concentration of 1 10 3 M? 1) 1 10 4 M 3) 1 10 11 M 1. If the [OH ] = 1 10 4 at 298 K for a given solution, the [H + ] of the solution is equal to 1) 1 10 14 3) 1 10 6 2) 1 10 10 4) 1 10 4 2. Based on Reference Table V, which is the strongest base? 1) NO

More information

4. Acid Base Chemistry

4. Acid Base Chemistry 4. Acid Base Chemistry 4.1. Terminology: 4.1.1. Bronsted / Lowry Acid: "An acid is a substance which can donate a hydrogen ion (H+) or a proton, while a base is a substance that accepts a proton. B + HA

More information

4.1 Stoichiometry. 3 Basic Steps. 4. Stoichiometry. Stoichiometry. Butane Lighter 2C 4 H 10 + 13O 2 10H 2 O + 8CO 2

4.1 Stoichiometry. 3 Basic Steps. 4. Stoichiometry. Stoichiometry. Butane Lighter 2C 4 H 10 + 13O 2 10H 2 O + 8CO 2 4. Stoichiometry 1. Stoichiometric Equations 2. Limiting Reagent Problems 3. Percent Yield 4. Limiting Reagent Problems 5. Concentrations of Solutes 6. Solution Stoichiometry 7. ph and Acid Base Titrations

More information

CHAPTER 16: ACIDS AND BASES

CHAPTER 16: ACIDS AND BASES CHAPTER 16: ACIDS AND BASES Active Learning: 4, 6, 14; End-of-Chapter Problems: 2-25, 27-58, 66-68, 70, 75-77, 83, 90-91, 93-104 Chapter 15 End-of-Chapter Problems: 69-74, 125, 129, 133 16.1 ACIDS AND

More information

Worked solutions to student book questions Chapter 4 Analysing acids and bases

Worked solutions to student book questions Chapter 4 Analysing acids and bases Q. Antacid tablets should normally be chewed before they are swallowed. Why? A. Antacid tablets are normally chewed to provide a larger surface area for faster reaction with stomach acids. Q. A laboratory

More information

Chem 321 Lecture 13 - Acid-Base Titrations 10/10/13

Chem 321 Lecture 13 - Acid-Base Titrations 10/10/13 Student Learning Objectives Chem 321 Lecture 13 - Acid-Base Titrations 10/10/13 Indicators A common end point for acid-base titrations is the color change associated with an acid-base indicator. An acid-base

More information

6) Which compound is manufactured in larger quantities in the U.S. than any other industrial chemical?

6) Which compound is manufactured in larger quantities in the U.S. than any other industrial chemical? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which statement concerning Arrhenius acid-base theory is not correct? A) Acid-base reactions must

More information