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1) The enthalpy change for the following reaction is -483.6 kJ:
2H2 (g) + O2 (g) → 2H2O (g)
Therefore, the enthalpy change for the following reaction is ________ kJ.
4H2 (g) + 2O2 (g) → 4H2O (g)
A) -483.6
B) -967.2
C) 2.34 x 105
D) 483.6
E) 967.2
2) George is making spaghetti for dinner. He places 4.01 kg of water in a pan and brings
it to a boil. Before adding the pasta, he adds 58 g of table salt (NaCl) to the water and
again brings it to a boil. The temperature of the salty, boiling water is ________oC.
Assume a pressure of 1.00 atm and negligible evaporation of water. Kb for water is 0.52
oC/m.
A) 99.87
B) 100.26
C) 100.13
D) 99.74
E) 100.00
3) Of the objects below, ________ is the most dense.
A) an object with a volume of 2.5 L and a mass of 12.5 kg
B) an object with a volume of 139 mL and a mass of 93 g
C) an object with a volume of 0.00212 m3 and a mass of 4.22 X 104 mg
D) an object with a volume of 3.91 X 10-24 nm3 and a mass of 7.93 X 10-1 ng
E) an object with a volume of 13 dm3 and a mass of 1.29 X 103 g
4) Gravitational forces act between objects in proportion to their ________.
A) volumes
B) masses
C) charges
D) polarizability
E) densities
5) In the periodic table, the elements touching the steplike line are known as ________.
A) transition elements
B) noble gases
C) metalloids
D) nonmetals
E) metals
6) Which choice is one of the suspected carcinogens by-products from water
chlorination called THMs?
A) CHClBr2
B) Cl2
C) Br2
D) CH3OCH3
E) CH4
7) ________ acts as a kind of energy bank in the body, and is found concentrated in
muscles and liver.
A) Lactose
B) Starch
C) Cellulose
D) Glycogen
E) Sucrose
8) The change in the internal energy of a system that absorbs 2,500 J of heat and that
does 7,655 J of work on the surroundings is ________ J.
A) 10,155
B) 5,155
C) -5,155
D) -10,155
E) 1.91 x 107
9) In the reactions involved in the photodecomposition of ozone (shown below), what
does M symbolize?
1. O2 (g) + h½ --> O (g) + O (g)
2. O (g) + O2 (g) + M (g) --> O3 (g) + M* (g)
3. O3 (g) + h½ --> O2(g) + O (g)
4. O (g) + O (g) + M (g) --> O2(g) + M* (g)
A) mesosphere
B) metal
C) molybdenum
D) methane
E) molecule
10) The solubility of manganese (II) hydroxide (Mn(OH)2) is 2.2 x 10-5 M. What is the
Ksp of Mn(OH)2?
A) 1.1 x 10-14
B) 4.3 x 10-14
C) 2.1 x 10-14
D) 4.8 x 10-10
E) 2.2 x 10-5
11) Given the following reactions
N2 (g) + O2 (g) → 2NO (g) ΔH = +180.7 kJ
2NO( g) + O2 (g) → 2NO2 (g) ΔH = -113.1 kJ
the enthalpy for the decomposition of nitrogen dioxide into molecular nitrogen and
oxygen
2NO2 (g) → N2 (g) + 2O2 (g)
is ________ kJ.
A) 67.6
B) -67.6
C) 293.8
D) -293.8
E) 45.5
12) What is the purpose of adding sodium tripolyphosphate to a detergent?
13) Which halogen, bromine or iodine, will form the more polar bond with phosphorus?
14) The Earth's ozone layer is located in the ________.
15) A solution of ammonia is 2.0% ionized at 25.0 oC. What was the original
concentration (in M) of the ammonia solution? The Kb at 25.0 oC for ammonia is 1.8 x
10-5.
16) The approximate pH of acid rain is ________.
17) Find the temperature (in K) above which a reaction with a H of 123.0 kJ/mol and a
S of 90.00 J/K mol becomes spontaneous.
