Problem 1
When 500.0 mL of 0.10 M NaOH solution (containing Na+ and OH- ions) is mixed with 500.0 mL of 0.10 M Mg(NO3)2 solution (containing Mg2+ and NO3- ions) a precipitate of solid Mg(OH)2 forms, and the resulting aqueous solution has pH = 9.43. Based on this information, determine the value of Ksp for Mg(OH)2. Show your reasoning clearly.
Problem 2
0.30 moles of HOCl are added to sufficient water to make 1.0 L of solution at 25 °C. Finish the table The Ka of HOCl, at 25 °C, is 2.9 × 10-8, determine x.
Problem 3
A certain gaseous hydrocarbon is found to be 88.8% C and 11.2% H by mass. The compound has a density of 2.12 g/L at 31 °C and 742 torr.
a) What is the empirical formula of the compound?
b) What is the molecular weight of the compound?
c) What is the molecular formula of the compound? d) Draw a possible structural formula for the compound.
Problem 4
Salicylic acid (shown below) is a weak acid with Ka = 3.0 × 10-4.
a) Complete the following reaction of salicylic acid with water.
b) Calculate the pH of 50 mL of 0.15 M salicylic acid.
Problem 5
a) Write a chemical equation that describes the dissolution of solid AuCl3 to Au3+ and Cl- ions found in water.
b) Write the expression for the Ksp of AuCl3.
c) Calculate how many grams of Au3+ would be found in one liter of a saturated solution of AuCl3. The Ksp for AuCl3 is 3.2 × 10-23.
Problem 6
Assume that you dissolve 10.0 g of a mixture of NaOH and in 250.0 mL of water and titrate with 1.50 M hydrochloric acid. The titration is complete after 108.9 mL of the acid has been added. What is the mass in grams of each substance in the mixture?