SCH3U0 - Acids & Bases Worksheet
1. Explain the meaning of the terms "strong" and "weak" when applied to acids and bases.
2. Give examples of a strong acid, a strong base, a weak acid and a weak base.
3. Phosphoric acid is the active ingredient in many commercial rust-removing solutions. Calculate the
volume of concentrated phosphoric acid (14.6 M) that must be diluted to prepare 500 mL of a 1.25 M
solution? 42.81 mL
4. How did Arrhenius define and acid and a base?
5. Pure HClO4 is molecular. Write an equation for its dissolution in water.
6. What is the difference between a strong electrolyte and a weak electrolyte?
7. If a substance is a weak electrolyte, what does this mean in terms of the tendency of the ions to react to
form the molecular compound? How does this compare with strong electrolytes?
8. Nitrous acid, HNO2, is a weak acid. Write an equation showing its reaction with water.
9. Hydrazine is a toxic substance that can be formed when household ammonia is mixed with bleach such
as CloroxTM. Its formula is N2H4 and it is a weak base. Write a chemical equation showing its reaction with
water.
10. HClO3 is a strong acid. Write an equation for its reaction with water.
11. Formic acid, HCHO2, is the substance that is responsible for the painful bites of fire ants. It is a weak
electrolyte and reacts with water in the same manner as acetic acid. Write a chemical equation that shows
its ionization in water.
12. Write the formula for the conjugate bases for each of these acids:
a) HCl; b) CH4; c) HSO3-1; d) H2SO4; e) NH3; f) HClO4
ClCH3SO32SO42NH2ClO413. Show how each of these acids react with water and forms a conjugate acid-base pair:
a) HCl; b) HNO3; c) H2SO4; d) HClO4; e) H2S; f) H3PO4
14. Calculate the molarity of a solution that contains 10 grams of HCl in 100 mL of solution. 2.74 mL
15. A solution contains 0.1 mole of HC2H3O2 dissolved in 0.5 L of solution. Calculate the molarity of the
solution. 0.2 mol/L
16. 500 mL of a solution contain 0.1 mole of HC2H3O2. The solution is diluted with water to the 1 L mark.
Calculate the molarity of the resulting solution. 0.05 mol/L
17. A 250 mL solution of H2SO4 has strength of 0.2 M. The solution is diluted with water to the 1 L mark.
What is the molarity of the solution so formed? 0.05 mol/L
18. If 0.3 mole of acetic acid is present in 150 mL of solution, calculate the molarity of the acid solution.2
mol/L
19. How many moles of acetic acid are required to make 125 ml of a 0.5 M solution? 0.0625 mol/L
20. To what volume must 125 mL of a 2 M solution of HCl be diluted to make the solution 0.05M?
5000mL = 5L
21. What is the concentration of a solution formed by diluting 300 mL of a solution containing 0.1 mole of
HCl to 6 L? 0.005 mol/L
22. Give directions for preparing 2.0 L of 0.250 mol/L HCl using 11.7 M HCl. 42.7 mL
23. Give directions for preparing 5.00 L of 0.15 mol/L H2SO4 using 18.0 M H2SO4. 41.6 mL
24. What volume of 2.00 mol/L HNO3 is needed to yield 10.00 grams of HNO3? 79.34 mL
pH Calculations
1.
What is the pH of a 0.0010 M HCl solution?
a) 0.0
b) 1.0
c) 2.0
d) 3.0
e) 4.0
2. What is the molar concentration in a solution of pH 5.50?
a) 5.50 M b) 3.2 X 10-5 M c) 5.0 X 10-5 M
d) 3.2 X 10-6 M e) 3.2 X 10-1 M
3. What hydrogen ion concentration corresponds to a pH of 8.64?
a) 0.94 M b) 4.4 X 10-6 M c) 2.3 X 10-6 M
d) 4.4 X 10-9 M e) 2.3 X 10-9 M
4. What is the hydrogen ion concentration in a solution of pH 5.76?
a) 1.74 X 10-6 M
b) 5.76 X 10-6 M c) 2.40 X 10-6 M
-5
d) 5.76 X 10 M e) 7.64 X 10-5 M
5. What is the [H+] in a 0.15 molar solution of acetic acid in water at 25oC? Acetic acid is 1.3%
dissociated.
a) 1.10 X 10-2 M
b) 1.95 X 10-3 M c) 1.20 X 10-4 M
d) 1.80 X 10-5 M e) 2.75 X 10-6 M
6. What is the H+ ion concentration of an aqueous solution that has a pH of 11?
a) 1.0 X 10-11 M
b) 1.00 X 10-3 M c) 3.0 X 10-1 M d) 11 X 10-1 M
7. If an aqueous solution has a [OH-1] = 3.0 X 10-11, the solution would be
a) an acidic solution b) a basic solution c) a neutral solution d) a salty solution
8. The pH of a solution in which the hydroxide ion concentration is 2.00 X 10-3 mol/L is
a) 1.70
b) 2.70
c) 11.0
d) 11.3
9. The pH of a solution is 5. The hydrogen ion and hydroxide ion concentrations are:
a) [H+1] = 1.0 X 10-9 M; [OH-1] = 1.0 X 10-5 M
b) [H+1] = 1.0 X 10-5 M; [OH-1] = 1.0 X 10-5 M
c) [H+1] = 1.0 X 10-5 M; [OH-1] = 1.0 X 10-9 M
d) [H+1] = 1.0 X 10-7 M; [OH-1] = 1.0 X 10-9 M
10. The pOH of 0.00010 M nitric acid solution is
a) 1.0 X 10-10 b) 1.0 X 10-4 c) 10
d) 4.0
11. How are acidic, basic, and neutral solutions in water defined;
a) in terms of [H+1] and [OH-1] Acidic H+ > 1x10-7, Basic H+ < 1x10-7, Neutral = 1x10-7
b) in terms of pH Acidic < 7, basic >7, neutral =7
12. A sodium hydroxide solution is prepared by dissolving 6.0 g of NaOH in 1.00 L of water. What is the
pOH and pH of this solution? pOH = 0.823, pH = 13.2
13. A solution was made by dissolving 0.837 grams of Ba(OH)2 in 100 mL of water. If Ba(OH)2 is fully
dissociated into ions what is the pOH and pH of the resulting solution? pOH = 1.01, pH = 12.99
14. What is the pH and pOH of a solution made by adding 400 mL of distilled water to 10 mL of 0.010 M
HNO3? You may assume that volumes are additive. pH = 3.61, pOH = 10.39
15. What is the [OH-1] and pH of these solutions:
a) 5.6 mg of KOH dissolved in 100 mL of solution. [OH-] = 9.9 x10-4 and pH = 10.99
b) 74 mg of Ca(OH)2 dissoved in 2.0 litres of solution. [OH-] = 1.997 x10-3 and pH = 11.30