Solutions Sample Problems
Name ________________________________________
Honors Chemistry
Date ________________________ Period _________
Acids and Bases
1)
A. [H3O+1] = 3.0 x 10-5M
pH = ___________
2)
A. [OH-1] = 6.5 x 10-3M
pOH = ___________
B. pH = 6.200
[H3O+1] = _____________________
B. pOH = 10.35
[OH-1] = _____________________
3) [H3O+1] = 8.2 x 10-9M. What is pOH?
4) Find the pH of a solution if [KOH] is 0.0060 M.
5) Calculate the pH of 0.050 M Ba(OH)2.
6) Excess lead(II) carbonate reacts with 27.5 mL of 3.00M nitric acid. Calculate the mass of lead(II) nitrate formed.
7) Calculate the volume, in mL, of a 0.324 molar solution of sulfuric acid required to react completely with 2.792 g of
sodium carbonate.
8) Solutions of sodium hydroxide are used to unclog drains. A 43.0 mL volume of sodium hydroxide was titrated with
32.0 mL of 0.100 M HCl. What is the molarity of the sodium hydroxide solution?
9) A volume of 25.0 mL of 0.120M sulfuric acid neutralizes 40.0mL of a sodium hydroxide solution. What is the
concentration of the sodium hydroxide solution?
Review: Solve for ∆H in the following problems:
10) Calculate for ∆H the reaction 2 Al (s) + 3 Cl2 (g) → 2 AlCl3 (s) from the data.
2 Al (s) + 6 HCl (aq) →2 AlCl3 (aq) + 3 H2 (g)
∆H = -1049. kJ
HCl (aq) →HCl (g)
∆H = +74.8 kJ
H2 (g) + Cl2 (g) → 2 HCl (g)
∆H = -1845. kJ
AlCl3 (s) → AlCl3 (aq)
∆H = -323. kJ
11) Determine ∆H using heats of formation. Hint: Make sure to balance the equation.
NH3 (g) +
O2
→
NO2
+
H2O(g)
12) Determine ∆H for the combustion of ethane (C2H6) using bond energies: C2H6
+
5O2 → 3CO2
+
4H2O
New Method: Solving for ∆H using Calorimetry
13) When a 15.3 g sample of KOH dissolves in 70.0 g of water in a calorimeter, the temperature rises from 22.4˚C to
66.4˚C. Calculate the ∆H for the process and write it on the correct side of the equation.
KOH (s)
→
K+(aq)
+
OH- (aq)
∆H = ?
14) When 16.9 g of sodium hydroxide solution reacts with 50.0 mL of hydrochloric acid solution, the temperature rises
from 21.3˚C to 30.9˚C.
a. What is the ΔHrxn in kJ/mol?
b. Write the net ionic, thermochemical equation for this reaction.
c. Draw an energy diagram for this reaction.