Acids and Bases Practice Problems
Auto-Ionization of Water and Calculating [H3O+] and [OH-]
Classwork:
1) If we have a solution with a hydronium concentration of 7.81x10-11M, what is the
hydronium concentration?
2) If we have a solution with a hydroxide concentration of 5.61x10-5M, what is the
hydronium concentration?
3) Given two beakers, one with pure water and the other with a hydroxide
concentration of 2.16x10-3M:
a. Which solution has more Hydronium?
b. Assuming each beaker contains 500.mL of solution, calculate the
difference in [OH-].
c. Assuming each beaker contains 500.mL of solution, calculate the
difference in [H3O+].
d. Assuming each beaker contains 500.mL of solution, calculate the
difference in moles of Hydronium.
4) Given two beakers, one with pure water and the other with a hydronium
concentration of 4.78x10-9M:
a. Which solution has more Hydroxide?
b. Assuming each beaker contains 650.mL of solution, calculate the
difference in [H3O+].
c. Assuming each beaker contains 650.mL of solution, calculate the
difference in [OH-].
d. Assuming each beaker contains 650.mL of solution, calculate the
difference in moles of Hydroxide.
Homework:
5) Water has a disassociation constant (Kw) of 1x10-14. Explain why this tells us that
water is not likely to disassociate. Use calculations to support your answer.
6) If we have a solution with a hydroxide concentration of 7.10x10-9M, what is the
hydronium concentration?
7) If we have a solution with a hydroxide concentration of 1.23x10-8M, what is the
hydronium concentration?
8) Given two beakers, one with pure water and the other with a hydroxide
concentration of 5.67x10-10M:
a. Which solution has more Hydronium?
b. Assuming each beaker contains 250.mL of solution, calculate the
difference in [OH-].
c. Assuming each beaker contains 250.mL of solution, calculate the
difference in [H3O+].
d. Assuming each beaker contains 250.mL of solution, calculate the
difference in moles of Hydronium.
9) Given two beakers, one with pure water and the other with a hydronium
concentration of 8.93x10-3M:
a. Which solution has more Hydroxide?
b. Assuming each beaker contains 750.mL of solution, calculate the
difference in [H3O+].
c. Assuming each beaker contains 750.mL of solution, calculate the
difference in [OH-].
d. Assuming each beaker contains 750.mL of solution, calculate the
difference in moles of Hydroxide.
Identifying Acids and Bases
Classwork:
10) A Sodium Hydroxide solution has a [OH-] of 2.67x10-2M.
a. Write the disassociation equation of solid Sodium Hydroxide in water.
b. Based on the disassociation equation and Arrhenius’s definitions of acids
and bases, is the solution an acid or a base? Explain
c. Based on the disassociation equation and the Bronsted and Lowery
definitions of acids and bases, is the solution an acid or a base? Explain
d. Based on the disassociation equation Lewis’s definitions of acids and
bases, is the solution an acid or a base? Explain
11) A Vinegar (CH3COOH) solution has a [H3O+] of 9.76x10-4M.
a. Write the disassociation equation of solid Sodium Hydroxide in water.
b. Based on the disassociation equation and Arrhenius’s definitions of acids
and bases, is the solution an acid or a base? Explain
c. Based on the disassociation equation and the Bronsted and Lowery
definitions of acids and bases, is the solution an acid or a base? Explain
d. Based on the disassociation equation Lewis’s definitions of acids and
bases, is the solution an acid or a base? Explain
Homework:
12) A Sodium Hydroxide solution has a [OH-] of 2.67x10-2M.
a. Write the disassociation equation of solid Sodium Hydroxide in water.
b. Based on the disassociation equation and Arrhenius’s definitions of acids
and bases, is the solution an acid or a base? Explain
c. Based on the disassociation equation and the Bronsted and Lowery
definitions of acids and bases, is the solution an acid or a base? Explain
d. Based on the disassociation equation Lewis’s definitions of acids and
bases, is the solution an acid or a base? Explain
13) An Ammonia (NH3) solution has a [H3O+] of 3.14x10-9M.
a. Write the disassociation equation of solid Sodium Hydroxide in water.
b. Based on the disassociation equation and Arrhenius’s definitions of acids
and bases, is the solution an acid or a base? Explain
c. Based on the disassociation equation and the Bronsted and Lowery
definitions of acids and bases, is the solution an acid or a base? Explain
d. Based on the disassociation equation Lewis’s definitions of acids and
bases, is the solution an acid or a base? Explain
Identifying Conjugate Acids and Bases
Classwork:
14) For Sodium Hydroxide
a. Write the reaction Sodium Hydroxide undergoes in water
b. Identify which reactants act as an acid or a base
c. Identify which products are the conjugate bases and acids
15) For Ammonia
a. Write the reaction Ammonia undergoes in water
b. Identify which reactants act as an acid or a base
c. Identify which products are the conjugate bases and acids
16) For Hydrochloric Acid
a. Write the reaction Hydrochloric Acid undergoes in water
b. Identify which reactants act as an acid or a base
c. Identify which products are the conjugate bases and acids
17) For the auto-ionization of water
a. Write the reaction water undergoes when it auto-ionizes
b. Identify which reactants act as an acid or a base
c. Identify which products are the conjugate bases and acids
Homework:
18) For Hydrobromic Acid
a. Write the reaction Hydrobromic Acid undergoes in water
b. Identify which reactants act as an acid or a base
c. Identify which products are the conjugate bases and acids
19) For Vinegar
d. Write the reaction Vinegar undergoes in water
e. Identify which reactants act as an acid or a base
f. Identify which products are the conjugate bases and acids
20) For Potassium Ion
g. Write the reaction Potassium Ions undergo in water
h. Identify which reactants act as an acid or a base
i. Identify which products are the conjugate bases and acids
Calculating pH
Classwork:
21) If the H+ concentration is 0.0001 mol/L , what is the pH?
22) If the H+ concentration is 0.00000001M , what is the pH?
23) If the H+ concentration is 0.00024 mol/L , what is the pH?
24) If the pH is 2.00, what is the H+ concentration ?
25) If the pH is 10.00, what is the H+ concentration ?
26) If the pH is 4.30, what is the H+ concentration ?
27) If the pH is 9.10, what is the H+ concentration ?
Homework:
28) If the H+ concentration is 0.089 mol/L , what is the pH?
29) If the H+ concentration is 8.4 x10-11M , what is the pH?
30) If the H+ concentration is 2.1 x 10-4 mol/L , what is the pH?
31) If the H+ concentration is 6.7 x10-8M , what is the pH?
32) If the pH is 6.34, what is the H+ concentration ?
33) If the pH is 3.89, what is the H+ concentration ?
34) If the pH is 5.712, what is the H+ concentration ?
Calculating pOH
Classwork:
35) If the H+ concentration is 0.0001 mol/L , what is the pOH?
36) If the H+ concentration is 0.00000001M , what is the pOH?
37) If the H+ concentration is 0.00024 mol/L , what is the pOH?
38) If the [H+] of a solution is 5.43x10-4M calculate the pOH.
39) If the [H+] of a solution is 9.37x10-11M calculate the pOH.
Homework:
40) If the H+ concentration is 0.089 mol/L , what is the pOH?
41) If the H+ concentration is 8.4 x10-11M , what is the pOH?
42) If the H+ concentration is 2.1 x 10-4 mol/L , what is the pOH?
43) If the H+ concentration is 6.7 x10-8M , what is the pOH?
44) What is the pOH of a solution with a hydronium concentration of 3.14x10-5M?
45) What is the pH of a solution with a Hydroxide concentration of 6.71x10 -13M?