Page 339 - Theory and Problems of BEGINNING CHEMISTRY

328 PRACTICE QUIZZES

Chapter 11 (15 minutes)
1. Calculate the concentration of each ion in solution after 225 mL of 0.100 M BaCl 2 is treated with
208 mL of 0.250 M NaCl and diluted to 0.500 L.

2. Calculate the concentration of each ion in solution after 225 mL of 0.100 M Ba(OH) 2 is treated with
208 mL of 0.250 M HCl and diluted to 0.500 L.

Chapter 12 (15 minutes)
1. Calculate the volume occupied by 0.0250 mol of chlorine at STP.

2. Calculate the volume of oxygen gas, collected over water at 836 torr barometric pressure and 298 K, that
◦
can be prepared by the thermal decomposition of 2.40 g of KClO 3 .(P water = 24 torr at 25 C)
Chapter 13 (10 minutes)
1. Calculate the ratio of the average velocity of neon molecules to argon molecules. Both gases are at the same
temperature.

2. If two gases are at the same temperature, which of the following must be true?
(a) The average speeds of their molecules must be the same.
(b) Their pressures must be the same.
(c) The average kinetic energies of their molecules must be the same.
(d) Their rates of effusion must be the same.
(e) Their numbers of molecules must be the same.

Chapter 14 (10 minutes)
1. Identify the oxidation state of the underlined element in each of the following:
(a)HNO 3 (b)Na 2 O 2 (c)Na 2 Cr O 7 (d)CF 4
2
2. Complete and balance the following equation in acid solution:

2− − 3+
Cr 2 O 7 + Cl 2 −→ ClO 3 + Cr

Chapter 15 (15 minutes)
1. Calculate the molality of alcohol in an aqueous solution with mole fraction alcohol 0.150.

2. Calculate the mole fraction of a solution 20.0% by mass methanol (CH 4 O) in water.

Chapter 16 (15 minutes)
1. Write an equilibrium constant expression for the following reaction:

2C(s) + O 2 (g) −− 2CO(g)
−−
2. Calculate the concentration of each substance at equilibrium if 0.0700 mol N 2 and 0.100 mol O 2 are placed
in a 1.00-L vessel and allowed to come to equilibrium according to the following equation:

N 2 (g) + 2O 2 (g) −− 2NO 2 (g) K = 6.0 × 10 −6
−−