Chem 30A Final Practice Exam
1) Which statement regarding balanced chemical equations is not true?
A) The number of each kind of atoms must be the same on each side.
B) Reactants are written to the left of the arrow.
C) Subscripts may be changed to make an equation simpler to balance.
D) When no coefficient is written in front of a formula, the number "one" is assumed.
E) Coefficients are used in front of formulas to balance the equation.
2) When the reaction shown is correctly balanced, the coefficients are:
HNO3 + KOH
KNO3 + H2O
A) 1, 1, 1, 1
B) 0, 0, 0, 0
C) 2, 2, 2, 2
D) 2, 1, 2, 1
E) 3, 1, 1, 3
3) Which reaction is an example of both a precipitation and a neutralization?
A) (NH4)2CO3 (s)
2 NH3 (g) + CO2 (g) + H2O (l)
B) H3PO4 (aq) + 3 KOH (aq) K3PO4 (aq) + 3 H2O (l)
Fe(OH)3 (s) + 3 KCl (aq)
C) FeCl3 (aq) + 3 KOH (aq)
D) 2 C (s) + O2 (g)
2 CO (g)
E) H2SO4 (aq) + Ba(OH)2 (aq)
BaSO4 (s) + 2 H2O (l)
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4) What fourth period element is represented by the dot structure shown?
A) Ca
B) Co
C) K
D) Br
E) Mn
5) The molar mass of Fe(OH)3 is ________ g.
A) 89.87
B) 106.87
C) 72.86
D) 104.86
E) 74.88
6) What is the most likely charge on an ion formed by an element with a valence electron
configuration of ns2np4?
A) 2B) 1C) 6+
D) 2+
E) 4+
7) 42.0 g Cl2 contains ________ molecules Cl2.
A) 0.592
B) 3.57 × 10-23
C) 1.78 × 1023
D) 1.18
E) 3.57 × 1023
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8) A thimble of water contains 4.0 × 1021 molecules. The number of moles of H2O is:
A) 2.4 × 1045
B) 2.4 × 10-23
C) 6.6 × 10-23
D) 2.4 × 1023
E) 6.6 × 10-3
9) Which of the following cannot have hydrogen bonds?
A) H2O
B) NH3
C) CH3NH2
D) HCl
E) HF
10) A sample of gas has a volume of 135 mL at 0.600 atm. What would be the volume if the
pressure is decreased to 0.200 atm while temperature is held constant?
A) 405 mL
B) 135 mL
C) 101 mL
D) 180 mL
E) 45.0 mL
11) What is the molarity of a solution prepared by dissolving 10.0 g of acetone, C3H6O, in
enough water to make 125 mL of solution?
A) 0.0214 M
B) 4.65 M
C) 1.38 M
D) 0.0125 M
E) 0.0465 M
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12) For the dot structure shown the most likely elements are X =________ and Y = ________.
A) carbon; fluorine
B) carbon; oxygen
C) hydrogen; carbon
D) carbon; hydrogen
E) fluorine; carbon
13) The shell having n = 2 contains ________ subshells, ________ orbitals, and up to ________
electrons.
A) 4, 8, 16
B) 3, 6, 12
C) 2, 4, 8
D) 1, 2, 4
E) none of the above
14) An atom with a mass number of 58 and with 32 neutrons will have ________ protons.
A) 26
B) 58
C) 16
D) 32
E) 90
15) If heat is consumed during a reaction, the reaction is said to be ________.
A) endothermic
B) exothermic
C) exothermic
D) endergonic
E) can't tell.
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16) Activation energy can best be described as
A) the energy level of the products.
B) the difference in energy between reactants and the maximum energy.
C) the difference in energy between reactants and products.
D) the energy level of the reactants.
E) the maximum energy level of the reaction.
Select the correct figure to match the description.
17) A slow reaction with a large negative free energy change
18) Which factors would decrease the rate of a reaction?
I. Lowering the temperature
II. Increasing the concentration of reactants
III. Adding a catalyst
A) I and III
B) III only
C) II and III
D) II only
E) I only
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19) When a reaction system is at equilibrium
A) the reaction rate in the forward direction is at a maximum.
B) there is no more chemistry happening.
C) the rates of the reaction in the forward and reverse directions are exactly equal.
D) the amounts of reactants and products are exactly equal.
E) the reaction rate in the reverse direction is at a minimum.
20) What is the conjugate base of HSO4-?
A) OHB) H2SO4
C) H2SO3
D) SO42E) H3O +
21) Which statement is correct for pure water?
A) Pure water contains larger amounts of hydroxide, [OH-], ions than hydronium,
[H+], ions.
B) Pure water contains no ions.
C) Pure water is an electrolyte.
D) Pure water contains equal amounts of hydroxide, [OH-], and hydronium, [H+], ions.
E) Pure water contains larger amounts of hydronium, [H+], ions than hydroxide,
[OH-], ions.
22) Which solution is basic?
A) [H+] = 1.0 × 10-7
B) [H+] = 1.0 × 10-10
C) [OH-] = 1.0 × 10-10
D) [H+] = 1.0 × 10-4
E) [OH-] = 1.0 × 10-7
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23) Which of the following statements is correct?
A) In an acidic solution, [H+] < 10-7; [OH-] < 10-7.
B) In an acidic solution, [H+] < 10-7; [OH-] > 10-7.
C) In an acidic solution, [H+] > 10-7; [OH-] = 10-7.
D) In an acidic solution, [H+] > 10-7; [OH-] > 10-7.
E) In an acidic solution, [H+] > 10-7; [OH-] < 10-7.
24) What is the value of [H+] in a solution with pH = 10.82?
A) 1.03 M
B) 10.82 M
C) 6.6 × 10-4 M
D) 3.18 M
E) 1.5 × 10-11 M
25) What is the pH of a solution in which [H+] = 3.8 × 10-8 M?
A) 3.80
B) 6.58
C) 2.6 × 10-7
D) 7.42
E) 1.0 × 10-8
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26) The condensed structure of 2,4-dimethylhexane is ________.
A)
B)
C)
D) CH3CH2CH2CH3CH2CH2CH2CH3
E)
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27) Which molecule is an isomer of the molecule shown?
A)
B) CH3(CH2)4CH3
C)
D)
E)
28) The name of the following structure will include the following parent name:
A) hexane
B) ethane
C) pentane
D) butane
E) octane
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29) Two or more compounds with the same molecular formula but with the atoms connected
differently are referred to as
A) functional groups.
B) normal alkanes.
C) conformations.
D) constitutional isomers.
E) branched alkanes.
30) How many carbon atoms are there in the longest continuous chain of the molecule
shown?
(CH3)2CH (CH2)5 CH3
A) 8
B) 9
C) 7
D) 5
E) cannot be determined without additional information
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Answer Key
Testname: CHEM 30A FA2016 PRACTICE FINAL EXAM
C
2) A
3) E
4) D
5) B
6) A
7) E
8) E
9) D
10) A
11) C
12) A
13) C
14) A
15) A
16) B
17) A
18) E
19) C
20) D
21) D
22) B
23) E
24) E
25) D
26) E
27) E
28) D
29) D
30) A
1)
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