1 Which of the following would likely have a low melting point and boiling point?
3. What is the formula of Barium phosphide?
a. BaP
b. BaP2 c.
BaP3 d. Ba3P2
e. Ba2PO4
4. What is the formula for sodium nitrate?
a. NaNO3 b. Na3N c. NaN3 d. NaHNO2 e. Na2N3
8. What is the empirical formula for a compound that contains 33.3% carbon and 66.7% O?
a. CO b. C2O3 c. CO2 d. CO3 e. C2O5
9. If 3 mol of C2H6 were
allowed to react with 10 moles of O2 according to the equation
below, which is the excess reagent , and how much remains after all the
limiting reagent is consumed?
2 C2H6 + 7 O2 --> 4 CO2 + 6 H2O
a. C2H6, 0.33 mol b. C2H6, 0.14 mol c. O2, 0.5 mol d. O2, 1.66 mol e. none of these
10. Which of the following symbols appears in the net ionic equation for the reaction between strongly conducting solutions of K2CrO4 and Pb(NO3)2? Hint: this is the test for lead ions.
a. NO3 b. Pb(NO3)2 c. KNO3 d. K+ e. CrO4 2-
11. Which formula appears in the net ionic equation for the reaction of a weakly conducting solution of acetic acid (CH3COOH) with sodium hydroxide?
13. What is the specific heat capacity of benzene if 200 J of heat is required to raise the temperature of 45 g of benzene by 4.23oC?
a. 0.95 b. 1.05 c. 1.87 . d. 2.2 x 103 e. 18.8
14. What mass of Ba(OH)2*8 H2O (M = 315 g/mol) exists in a sample which requires 10 mL of 0.011 M sulfuric acid in a titration?
a. 0.0062 b. 0.013 c. 0.035 g d. 5.2 e. 34.7
15. What is the concentration of a solution prepared by diluting 60 mL of 0.033 M NaOH to 500 mL?
a. 0.275 b. 0.502 c. 0.0040 d. 6.7 x 10-4 e. 8.2 x 10-3
16. The enthalpy change measured for a reaction occurring in a styrofoam cup calorimeter includes energy involved in bond formation and destruction AND work done by expansion or contraction of the chemical system. a. True b. False
17. Which of the following reactions is exothermic?
a. H2O (s) H2O (l)
b. H2O (g) H2O (s)
c. H2O (l) H2O (g)
d. N2 (l) N2 (g)
e. N2 (s) N2 (g)
18. Which of the following equations has DeltaH equal to the heat of formation of NaOH?
a. Na + + OH - NaOH
b. Na + O + H NaOH
c. 2 Na + O2 + H2 2 NaOH
d. Na + ½ O2 + ½ H2 NaOH
e. Na + H2O NaOH + H+
19. Use the enthalpy change for the first two reactions to determine the enthalpy change for the third reaction:
2 SO2 (g) + O2 (g) 2 SO3 (g) -196.6 kJ
S(s) + O2 (g) SO2 (g) -297.0 kJ
2 CO + O2 2 CO2
a. 107 b. 85 c. 63 d. 52 e. 11
22. If a gas has a volume of 393 mL at 780 mm Hg and 30oC, at what temperature, in oC, would the volume be 500 mL, assuming no pressure change?
a. 24oC b. 38 oC c. 112 oC d. 178 oC e. 222 oC
23. Given a 8.32 g sample of H2S
(M = 34.09 g/mol), what volume (in L) would it occupy at 45oC
and 724 mm Hg pressure (R = 0.082 LAtm/Kmol)?
a. 10.2 L
b. 0.00124 L c. 1.1
x 103 L d. 6.69 L
e. 0.0124 L
24. What is the partial pressure of the gas collected over water in the burette at right if the atmospheric pressure is 76 cm Hg, the vapor pressure of water is 2 cm Hg, and the densities of water and mercury are 1.0 g/ml and 13.6 g/ml, respectively?
a. 65 cm Hg b. 73.3 cm Hg c. 78.7 cm Hg d. 77.3 cm Hg e. 72.2 cm Hg
25. One way to measure the molar mass of a gas is to measure its rate of effusion from a container with a small hole. The rate of effusion can be used as a measure of the velocity of the molecules. One type of freon, CCl2F2 (M = 121 g/mol) effuses at a rate of 33 mL/min, while another effuses at a rate of 22 mL/min. What is the molar mass of the second freon?
a. 54
b. 81 c. 181
d. 222 e. 272
26. When a porous cup connected to a manometer was immersed in a beaker containing freon, CCl2F2, the pressure in the porous cup
a. increased because freon is more dense than air.
b. increased because freon diffused into the porous cup
c. remained the same because the freon in the beaker and the air in the porous cup were the same.
d. decreased because molecules in air are moving faster than molecules of freon
e. none of these.