Chemistry 101 Lab Final B 11/25/98 Dr. B. Jackson
51. The volume of a gas is directly proportional with the temperature in Kelvin.
This is whose law? a) Gay Lussac b) Boyle c) Charles
52. To what temperature must a gas 500oC be cooled for its volume to
be one half the original volume?
a) 250oC b) 1000oC c) 387oC d) 194oC e)114oC
53. An irregular piece of metal with a mass of 8.0 grams was placed in a
graduated cylinder containing 5.0 mL of water. The water level moved to the
7.0 mL mark. What is the density of the metal?
a) 1.14 g/mL b) 2.0 g/mL c) 1.6 g/mL d) 4.0 g/mL e) 0.25 g/mL
54. To a test tube containing water, an unknown liquid was added. The unknown
liquid settled to the bottom of the test tube. The unknown was either acetone
(density 0.79 g/mL) or carbon tetrachloride (density 1.60 g/mL). What was the unknown?
a) acetone b) carbon tetrachloride c) not enough information given
55. To determine the normality of a solution of NaOH, 6.12 grams of potassium
hydrogen phthalate (MW 204) was dissolved in 50 mL water. It took 30 mL of the
NaOH solution to neutralize the phthalate. What is the normality of the NaOH
solution?
a) 0.03 b) 0.30 c) 0.01 d) 0.1 e) 1.0
56. It took 20 mL of a 0.1 N NaOH solution to neutralize 10 mL of a HCl solution.
What is the normality of the HCl solution?
a) 0.2 b) 0.1 c) 0.4 d) 0.05
57 - 58 A 10.0 gram mixture of ammonium chloride, sodium chloride, and silicon
dioxide in an evaporating dish (A) was heated and reweighed. The mixture now weighed
9.0 grams. Water was added to the remaining mixture and stirred. The water was
poured off into another evaporating dish (B). Both evaporating dishes were reweighed. The compound remaining in dish
A weighed 5.0 grams. The compound remaining in dish B weighed 4.0 grams.
57. What was the compound remaining in dish A?
a) ammonium chloride b) sodium chloride c) silicon dioxide
58. What was the percent ammonium chloride in the mixture?
a) 10% b) 90% c) 40% d) 50%
59. An unknown sample was subjected to thin layer chromotography. The distance
travelled by the solvent was 100 mm from the origin to the solvent front. One of
the components of the sample travelled 40 mm distance from the origin.
What is the Rf of the component?
a) 0.01 b) 0.40 c) 0.50 d) 1.00
60. In the notation AXE, which of the symbols represents the number of unbonded
electron pairs? a) A b) X c) E
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61. What is the AXE notation for ClO4 ?
a) AX2E1 b) AX3E1 c) AX4E0 d) AX2E2
62. Given the following reaction:
Na2CO3 + 2 HCl --------> 2 NaCl + H2O + CO2
A student reacted 0.53 grams of Na2CO3 and formed 0.53
grams of NaCl. What is the percent recovery?
a) 100% b) 91% c) 87% d) 73%
63. Can the temperature of a solid be lower than its freezing point?
a) yes b) no
64 - 65 A student was given 37.2 grams of a hydrated salt. The molecular weight of
the anhydous salt was 150. The sample was heated and now weighed 30.0 grams.
64. How many moles of anhydrous salt was present?
a) 0.2 b) 0.02 c) 1.2 d) 0.12
65. The formula for the hydrate is Salt * ___H2O.
a) 1 b) 2 c) 3 d) 4
66. There were 140 mm distance between the freezing point and the boiling point of
water on an uncalibrated thermometer. An unknown melted 50 mm distance from the
freeing point. What is the melting point of the unknown in oF?
a) 76oF b) 64oF c) 96oF d) 32oF
67. 100 mL of a 2 M HCl was reacted with 100 mL of a 2 M NaOH. The original temp-
erature of the acid and base solutions was 23oC. After mixing the temp-
erature rose to 45oC. How many calories were produced in this reaction?
a) 2200 b) 4400 c) 1100
68. In an acid solution
a) red litmus turns blue b) blue litmus turns red
69. The pH of a carbonated soft drink is
a) acidic b) basic c) neutral
70. This exam is on _______ paper.
a) white b) yellow
Ans: 51c; 52e; 53d; 54b; 55e; 56a; 57c; 58a; 59b; 60c; 61c; 62b; 63a; 64a; 65b; 66c;
67b; 68b; 69a