Chapter 15: Acids, Bases, and Salts. 15.1: Acids and Bases

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1 Chapter 15: Acids, Bases, and Salts Name: 15.1: Acids and Bases Define an Acid: Define a Base: Ex of an acid in aqueous solution: Ex of a base in aqueous solution: List some of the properties of acids & bases and some examples of each: ACIDS BASES What are the properties of acids caused by? What is the other name for this ion? Names and Uses of Common Acids: 1.) 2.) 3.) 4.) What are the properties of bases caused by? What is the other name for this ion? Names and Uses of Common Bases: 1.) 2.) 3.) Theories of Acids & Bases: Several theories have been proposed to answer the question What is an acid and what is a base? 1. Arrhenius Theory: Made by Svante Arrhenius in Define an Arrhenius acid: Ex: Define an Arrhenius base: Ex: 2. Bronsted-Lowry Theory: Made by Johannes Bronsted and Thomas Lowry in Define a Bronsted-Lowry acid: Define a Bronsted-Lowry base: Label the Bronsted-Lowry acid & base in the following chemical equation: HCl + H 2 O Cl - + H 3 O + Define a Conjugate acid: Define a Conjugate base: 1

2 In the following chemical equations, label which is the acid (A), base (B), conjugate acid (CA), and conjugate base (CB): HCl + H 2 O Cl - + H 3 O + H 2 O + NH 4 + H 3 O + + NH 3 Determine the conjugate base for each of the following acids: 1. HF 2. H 2 SO 4 3. HNO 3 4. NH 4 +1 Determine the conjugate acid for each of the following bases: 1. OH NH H 2 O 4. NH 3 Define amphoteric: In the following 2 reactions, label the acids and bases, illustrating that water is amphoteric: Ex 1: H 2 O + NH 3 OH - + NH 4 + Ex 2: H 2 O + H 2 SO 4 HSO H 3 O + In Ex 1, H 2 O is acting as a(n): In Ex 2, H 2 O is acting as a(n): 3. Lewis Acid-Lewis Base Theory: Made by Gilbert Lewis in early 1920 s. Define a Lewis acid: Define a Lewis base: Ex: How is the Bronsted-Lowry theory related to the Lewis theory? Give an example: 15.2: Reactions of Acids Reaction with Bases: also called. The products are always. Examples: Complete and balance the following neutralization reactions. Then, give the names and formulas of the salt that will form: 1.) HCl + Ca(OH) 2 2.) HNO 3 + KOH 3.) H 2 SO 4 + Al(OH) 3 2

3 4.) NaOH + HBr Describe the term dissociation (aka ): 15.5: Electrolytes and Nonelectrolytes Define Electrolyte: Solutions that contain lots of ions (charged particles) will conduct an electric current! The 3 classes of electrolytes are: Examples: Define Nonelectrolyte: Examples: The main difference between electrolytes & nonelectrolytes is that electrolytes are capable of. Will a salt (NaCl) water solution conduct an electric current? How about a sugar (C 6 H 12 O 6 ) water solution? Why or why not? Define Strong Electrolyte: List of Common Strong Acids: List of Common Strong Bases: Write the equation for a strong acid being dissociated in water: Write the equation for a strong base being dissociated in water: Write the equation for the dissociation of table salt: Define Weak Electrolyte: List of Common Weak Acids: List of Common Weak Bases: Write the equation for a weak acid being dissociated in water: Write the equation for a weak base being dissociated in water: Dissociation Calculations: 1.) What is the molarity of each ion in a solution of 0.20 M NaCl? 3

4 2.) What is the molarity of each ion in a solution of 0.40 M K 2 SO 4? Draw and label the ph scale: 15.9: Introduction to ph The concentration of in solution is measured by the ph scale. Lower ph = Higher ph = What are the equations to find the ph or poh of a solution? Determine the ph of the following solutions and determine if it is acidic or basic: 1. [H + ] = 1.0 x M 2. solution with a poh of [H + ] = 6.0 x 10-8 M Acid/base? Acid/base? Acid/base? M HNO M H 2 SO 4 6. [OH - ] = 1.0 x 10-4 M Acid/base? Acid/base? Acid/base? Determine the [H + ] of the following solutions: 1. a solution with a ph of a solution with a ph of a solution with a poh of 6.1 What is a good way to test the ph of a solution? Where do we see this in real life? Define Titration: 15.10: Neutralization Define Equivalence Point (aka ): 4

5 Draw an example of the graph formed from a titration: The formula we use for these calculations is: * In this equation, must also look at Ex 1: ml of M NaOH solution is required to neutralize ml of HCl. What is the concentration of the HCl solution? Ex 2: It takes 0.50L of 4.0 M H 2 SO 4 solution to completely neutralize 2.0L of Ca(OH) 2 solution. What is the concentration of the Ca(OH) 2 solution? Ex 3: 42.5 ml of 1.3M KOH are required to neutralize 50.0 ml of H 2 SO 4. Find the molarity of H 2 SO 4. Define Acid Rain: 15.12: Acid Rain What is the ph of unpolluted rain? Why is unpolluted rain slightly acidic, and not neutral? What are some of the causes of acid rain? What are some of the effects of acid rain? Define Ocean Acidification: What was the ph of ocean water in the 1700 s (pre-industrial)? What was the ph of ocean water in the 1990 s? What are the main causes for ocean acidification? What are some of the harmful effects of such acidification? 5

6 Brønsted-Lowry Acid/Base Worksheet 1. What's the Brønsted definition of an acid?...of a base? 2. In 1923, Johannes Brønsted (Danish) and Thomas Lowry (British) independently expanded the definition of Arrhenius acids and bases. A Brønsted-Lowry acid is a molecule or ion that is a hydrogen ion (H + ) donor. The hydrogen ion is also called a. A Brønsted- base is a or ion that is a proton acceptor. A -Lowry acid-base reaction involves the transfer of protons from the to the base. The molecular species that remains after a Brønsted-Lowry acid has given up a is called the conjugate base of that acid. The molecular species that is formed after a Brønsted-Lowry base a proton is called the of that base. The conjugate pair refers to an acid and its conjugate or a base with its conjugate. Note that in a conjugate pair, there is no reason why the acid should be while the base is charged. 3. What is the correct name for the H3O + ion? 4. Determine the conjugate base for the following acids: HCl: HNO 3 : NH 4 + : H 2 O: H 3 PO 4 : 5. Determine the conjugate acid for the following bases: OH -1 : Br -1 : NH 3 : H 2 O: CO 3-2 : 6. Identify the conjugate acid/base pairs in the following reactions: a. HCN + H2O H3O + + CN acid: base: conjugate base: conjugate acid: b. H2O + HSO4 - SO4-2 + H3O + acid: base: conjugate base: conjugate acid: 7. Write the equation for the ionization of HNO3 in water, labeling each acid/base pair: 8. Write the equation for the ionization of CO3-2 (a weak base) in water, labeling each acid/base pair: 9. Some acids have a unique property: the ability to donate more than one proton (H+) per molecule. A molecule that can donate one proton is called a monoprotic acid. A molecule that donates two protons is a protic acid. A molecule that can donate three protons is called a acid. 10.) Complete the following: +1 a. the conjugate base of NH 4-2 c. the conjugate acid of CO 3-1 e. the conjugate base of HSO 4-2 g. the conjugate base of HC 6 H 3 O 5 b. the conjugate base of H 3 PO 4 d. the conjugate acid of H 2 O -1 f. the conjugate base of H 2 PO 4 h. the conjugate acid of C 2 H 6 NH 11.) A substance that is capable of donating or accepting a proton is called. 6

7 ph of Solutions Name: 1. What is the ph scale? 2. What is ph a measure of? 3. Why is pure water considered neutral on the ph scale? 4. What is the equation used for finding ph? 5. What is the equation that relates to ph and poh? 6. Classify each of the following as acidic, neutral, or basic. The ph of each item is also listed. a) tomatoes: 4.2 e) soil: 5.5 b) eggs: 7.8 f) milk: 6.4 c) ammonia: 11.0 g) bleach: 12.0 d) tap water: 7.2 h) lye (NaOH): Are the following solutions acidic, neutral, or basic? a) [H + ] = 1 x 10-8 M e) [OH - ] = 1 x 10-3 M b) [H + ] = 7.3 x 10-1 M f) [OH - ] = 1 x 10-7 M c) [H + ] = 1.0 M g) [OH - ] = M d) [H + ] = 1 x 10-5 M h) [OH - ] = 4.9 x 10-6 M 8. What would be the ph of each of the following: (DANGER beware of tricks!) a) M HCl g) M HCl b) M HNO 3 h) M KOH c) M NaOH i) M HCl d) M HCl j) M HCl e) 1.0 M HBr k) 12 M KOH f) 1.0 M KOH l) 12 M HCl 9.) A solution contains g HCl in 560. ml solution. a) Write the equation for the dissociation of HCl: b.) What is the molarity of the HCl solution? c) What is the [H+]? d) What is the [OH-]? 7