CHEM 1100

Practice Test 4

Note: These questions are representative of the types of questions you can expect on the test. The actual test will be longer, typically between 20-40 questions. You will need to bring a SCANTRON answer sheet to each test.

1. A sample of nitrogen gas has a volume of 32.4 L at 20 oC. The gas is heated to 220 oC at constant pressure. What is the volme of nitrogen?

a. 2.94 L
b. 19.3 L
c. 31.4 L
d. 54.5 L
e. 356 L

2. At what temperature will a fixed mass of gas with a volume of 125 L at 15 oC and 750 mm Hg occupy a volume of 101 L at a pressure of 645 m Hg?

a. - 73 oC
b. 10.4 oC
c. 2 oC
d. 34 oC
e. 200 oC

3. Calculate the density of CO2 (g) at 100 oC and 10.0 atm pressure.

a. 1.44 g/L
b. 134 g/L
c. 44.0 g/L
d. 53.6 g/L
e. 14.4 g/L

4. Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25 oC and 1.0 atm.    Given: R= 0.0821 L.atm/K.mol

a. 0.0186 L
b. 4.5 L
c. 11.2 L
d. 29.9 L
e. 53.7 L

5. How many liters of chlorine gas at 650 mm Hg and 25 oC can be produced by the reaction of 2.0 L of 2.5 M HCl solution with excess MnO2?

MnO2 (s) + 4 HCl (aq) ---> MnCl2 (aq) + 2 H2O (l) + Cl2 (g)

a. 1.25 L
b. 24.2 L
c. 35.7 L
d. 88.6 L
e. 143 L

6. An exothermic reaction causes the surroundings to:

a. warm up
b. become acidic
c. expand
d. decrease in temperature
e. release CO2

7. How much heat is required to raise the temperature of 2.0 kg of water from 10 oC to 80 oC.  Given: specific heat of water = 4.18 J/g.oC

a. 33 kJ
b. 0.585 kJ
c. 585 kJ
d. 585 J
e. 240 kJ

8. Find the standard enthalpy of formation of ethylene, C2H4 (g), given the following data:

C2H4 (g) + 3 O2 (g) ---> 2 CO2 (g) + 2 H2O (l)       DHfo = - 1411 kJ/mol

C (s) + O2 (g) ---> CO2                                              DHfo = - 393.5 kJ/mol

H2 (g) + ½ O2 (g) ---> H2O                                       DHfo = - 241.8 kJ/mol

a. 52 kJ
b. 140 kJ
c. 731 kJ
d. 1.41 x 103 kJ
e. 2.77 x 103 kJ

9. Use the following equation to determin how many grams of CaO must react in order to release 525 kJ of heat:

CaO (g) + H2O (l) ---> Ca(OH)2 (s)        DHo = - 64.8 kJ/mol

a. 6.92 g
b. 56.1 g
c. 455 g
d. 606 g
e. 34,000 g

10. Given that:

2 H2 (g) + O2 (g) ---> 2 H2O (l)                                   DHo = - 571 kJ/mol

C3H4 (g) + 4 O2 (g) ---> 3 CO2 (g) + 2 H2O (l)          DHo = - 1941 kJ/mol

C3H8 (g) + 5 O2 (g) ---> 3 CO2 (g) + 4 H2O (l)          DHo = - 2220 kJ/mol

Calculate DHo for the reaction:    C3H4 (g) + 2 H2 (g) ---> C3H8 (g)

a. - 292 kJ/mol
b. + 292 kJ/mol
c. +850 kJ/mol
d. - 850 kJ/mol
e. none of the above

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