Assignment #6 from Chemistry CD ROM
Chemical Equilibrium

The following problems are very similar to Chapter 13 problems from the CD ROM. Check out how those ones are solved and also read that chapter of the Study Guide and the associated worked examples. We will use two classes this week to work on the problems.

1. For both sides of each of the following equilibria determine which substance is a Brönsted-Lowry acid and which is a base. (All ions are aqueous.)

A) H₂SO₃ + HCO₃^-1 <=> HSO₃^- + H₂CO₃

B) HF + NH₃ <=> NH₄⁺ + F^-

C) CH₃COOH + NO₂^- <=> CH₃COO^- + HNO₂

D) NH₄⁺ + HSO₃^- <=> NH₃ + H₂SO₃

 

2. Using any other substance you wish as your acid, write a balanced equation showing each of the following acting as a Brönsted-Lowry base. A) CO₃^2-    B) HS^-     C) P^-3    D) NH₃

 

3. For each of the following determine [H₃O⁺], [OH^-], pH and pOH. All the substances are strong electrolytes:

A) 0.20 M HCl    

B) 2.0 g NaOH in .10 L  

C) 12.0 g HClO₄ in 158 mL of solution

 

4. Write the equation for the dissociation of each of the following.

A) HNO₃  

B) H₃PO₄  

C) H₂PO₄^-

D) CH₃COOH

 

5. When 50.0 mL of .100 M HCl and 49.0 mL of .100 M NaOH are mixed...

A) What is the [H₃O⁺]?

B) What is the [OH^-]?

C) What are the pH and pOH?

 

6. A solution of NaOH was titrated against potassium acid phthalate (KHP). It took 19.61 mL of the base to neutralize a 50.0mL sample of KHP (0.100M). What is the molarity of the base?

 

7.  Hydrofluoric acid (HF) has K_a = 6.5 x 10^-4.  Find the pH and pOH for 3.0 g of HF dissolved to make 100mL of acid in solution.