CHEM 1411
PRACTICE EXAM # 2 (Chp 4 and 5)
Name:__________________________
1. How many moles of N2 gas occupy 11.2 liters volume a STP condition?
A. 1.0 mol
B. 2.0 mol
C. 0.50 mol
D. cannot be determine
2. Which of the following is/are not characteristic of gases?
I. high density
II. formation of homogeneous mixtures III. low intermolecular forces
A. I only
B. I and III
C. I, II, and III
D. II and III
3. An unknown gas "X" effuses two times faster than a sample of SO3(g) through a porous container. Which of
the following is the unknown gas ?
A. H2
B. CH4
C. Ne
D. Ar
4. Which of the following are nonelectrolytes in water?
(i) HF
A. ii and iii
(ii) ethanol, C2H5OH
B. i, ii, and iii
(iii) CH3 OCH3
C. iii only
(iv) KClO3
D. ii only
5. How many milliliters of 1.50 M KOH solution are needed to supply 0.125 mole of KOH?
A. 0.0833 ml
B. 0.188 ml
C. 12.0 ml
D. 83.3 ml
6. Which of the following is/are soluble in water?
(i) NiCl2
A. iv only
(ii) Ag2S
(iii) Cs3PO4
B. i, ii, and iii
(iv) (NH4)2SO4
C. i, ii, and iv
D. i, iii and iv
7. Which of the following reactions will occur?
(i)Ni(s) + Zn2+(aq) 
(ii)Pb(s) + Ag+(aq) 
(iii)Zn(s) + Ca2+(aq) 
(iv)Al(s) + Fe2+(aq) 
A.
i only
B. ii only
C. ii and iv only
D. i and iii only
8. Which of the following is a weak base?
A. NaOH
9.
B. Ca(OH)2
C. NH4OH
D. RbOH
Which of these compounds is a strong electrolyte?
A. H2O
B. O2
C. H2SO4
D. C6H12O6 (glucose)
E. CH3COOH (acetic acid)
10.
11.
12.
Based on the solubility rules, which of these processes will occur when solutions of ZnSO4(aq) and
MgCl2(aq) are mixed?
A.
ZnCl2 will precipitate; Mg2+ and SO42- will be spectator ions.
B.
ZnSO4 will precipitate; Mg2+ and Cl- will be spectator ions.
C.
MgSO4 will precipitate; Zn2+ and Cl- will be spectator ions.
D.
MgCl2 will precipitate; Zn2+ and SO42- will be spectator ions.
E.
No precipitate will form.
Which choice gives the correct oxidation numbers for all three elements in Rb2SO3 in the order that
the elements are shown in the formula?
A. -2, +6, -2
B. -1, +4, -3
D. +1, +4, -2
E. +1, +6, -6
Identify the reducing agent in the chemical reaction
5Fe2+(aq) + MnO4-(aq) + 8H+(aq) 5Fe3+(aq) + Mn2+(aq) + 4H2O(l).
A. Fe2+
13.
C. +2, +4, -2
B. MnO4-
C. H+
D. Mn2+
E. Fe3+
Which of these chemical equations describes a halogen displacement reaction?
A.
2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
B.
2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)
C.
CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
D.
2KNO3(s)  2KNO2(s) + O2(g)
E.
2LiOH(aq) + H2SO4(aq)  Li2SO4(aq) + 2H2O(l)
14. How many liters of chlorine gas at 650 mmHg and 25C can be produced by the reaction of 2.00 L of
2.50 M HCl solution with excess MnO2?
MnO2(s) + 4HCl(aq)  MnCl2(aq) + 2H2O(l) + Cl2(g)
A.1.25 L
B. 24.2 L
C. 35.7 L
D. 88.6 L
E. 143 L
15. If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor
does the volume of the sample change?
A.8
B. 2
C. 1/2
D. 1/4
E. 1/8
16. 0.820 mole of hydrogen gas has a volume of 2.00 L at a certain temperature and pressure. What is the
volume of 0.125 mol of this gas at the same temperature and pressure?
A. 0.0512 L
B. 0.250 L
C. 0.305 L
D. 4.01 L
E. 19.5 L
17. A small bubble rises from the bottom of a lake, where the temperature and pressure are 4C and 3.0
atm, to the water’s surface, where the temperature is 25C and the pressure is 0.95 atm. Calculate
the final volume of the bubble if its initial volume was 2.1 mL.
A.0.72 mL
B. 6.2 mL
C. 41.4 mL
D. 22.4 mL
E. 7.1 mL
18. At what temperature will a fixed mass of gas with a volume of 125 L at 15C and 750 mmHg occupy
a volume of 101 L at a pressure of 645 mm Hg?
A.-73C
B.10.4C
C. 2C
D. 34C
E. 200C
19. Calculate the volume occupied by 25.2 g of CO2 at 0.84 atm and 25C.
A.0.060 L
B.1.34 L
C. 16.9 L
D. 24.2 L
E. 734 L
20. Calculate the density, in g/L, of SF6 gas at 27C and 0.500 atm pressure.
21.
A. 3.38  10-3 g/L
B. 2.96 g/L
D. 32.9 g/L
E.3.38 kg/L
What mass of Na2SO4 is needed to prepare 350. mL of a solution having a sodium ion concentration
of 0.125 M?
A. 3.11 g
22.
C. 22.4 g/L
B. 24.9 g
C. 12.4 g
D. 6.21 g
E. 8.88 g
Zinc dissolves in hydrochloric acid to yield hydrogen gas:
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
What mass of hydrogen gas is produced when a 7.35 g chunk of zinc dissolves in 500mL of 1.200
M HCl?
A. 0.605 g
B.0.113 g
C. 0.302 g
D. 0.453 g
E. 0.227 g
23. A sample of a gas occupies 1.40  103 mL at 25C and 760 mmHg. What volume will it occupy at the
same temperature and 380 mmHg?
A. 2,800 mL
B. 2,100 mL
C. 1,400 mL
D. 1,050 mL
E. 700 mL
25. The gas pressure in an aerosol can is 1.8 atm at 25C. If the gas is an ideal gas, what pressure would
develop in the can if it were heated to 475C?
A. 0.095 atm
B. 0.717 atm
C. 3.26 atm
D. 4.52 atm
E. 34.2 atm
Part II – Show All Your Work.
31. Write a complete ionic and net-ionic equation for the following reaction.
Pb(NO3)2 (aq) + Na2S (aq) 
32. a) What volume(ml) of 0.115 M HClO4 solution is required to neutralize 50.00 ml of 0.0875 M
Ca(OH)2 ?
b) A solution contains 3.2 g NaOH ( MW = 40) in 20.0 ml of solution. What is the molarity of the
solution?
33. 2.50 g CO2 gas occupies 5.60 liters at 789 torr.
a) Calculate the temperature of gas in 0C.
b) What is the density of CO2 gas at STP condition?
34. What volume of O2(g), measured at 22 °C and 763 torr, is consumed in the combustion of 7.50 L of
C2H6(g), measured at STP?
2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O(l)
35. A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample of the gas
occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at -4.0C. Which of the following is its
molecular formula?
36. Specify how each of the following strong electrolytes ionizes or dissociates into ions upon dissolving
in water.
a) KNO3
b) FeSO4
c) (NH4)2CO3
d) NaHCO3