Chapter 5 Thermochemistry
1) The internal energy of a system is always increased by ______.
A) adding heat to the system
B) having the system do work on the surroundings
C) withdrawing heat from the system
D) adding heat to the system and having the system do work on the surroundings
E) a volume compression
2) Which one of the following conditions would always result in an increase in the internal energy of a system?
A) The system loses heat and does work on the surroundings.
B) The system gains heat and does work on the surroundings.
C) The system loses heat and has work done on it by the surroundings.
D) The system gains heat and has work done on it by the surroundings.
E) None of the above is correct.
3) The value of ΔE for a system that performs 111 kJ of work on its surroundings and gains 89 kJ of heat is ______kJ.
A) -111
B) -200
C) 200
D) -22
E) 22
4) The value of ΔE for a system that performs 13 kJ of work on its surroundings and loses 9 kJ of heat is ______kJ.
A) 22
B) -22
C) -4
D) 4
E) -13
5) When a system ______, ΔE is always negative.
A) absorbs heat and does work
B) gives off heat and does work
C) absorbs heat and has work done on it
D) gives off heat and has work done on it
E) none of the above is always negative.
6) Which one of the following is an exothermic process?
A) ice melting
B) water evaporating
C) boiling soup
D) condensation of water vapor
E) Ammonium thiocyanate and barium hydroxide are mixed at 25 °C: the temperature drops.
7) Which of the following is a statement of the first law of thermodynamics?
A) Ek = (1/2) mv2
B) A negative ΔH corresponds to an exothermic process.
C) ΔE = Efinal - Einitial
D) Energy lost by the system must be gained by the surroundings.
E) 1 cal = 4.184 J (exactly)
8) A ______ΔH corresponds to an ______process.
A) negative, endothermic
B) negative, exothermic
C) positive, exothermic
D) zero, exothermic
E) zero, endothermic
9) A ______ΔH corresponds to an ______process.
A) negative, endothermic
B) positive, exothermic
C) positive, endothermic
D) zero, exothermic
E) zero, endothermic
10) ΔH for an endothermic process is ______while ΔH for an exothermic process is ______.
A) zero, positive
B) zero, negative
C) positive, zero
D) negative, positive
E) positive, negative
11) For a given process at constant pressure, ΔH is negative. This means that the process is ______.
A) endothermic
B) equithermic
C) exothermic
D) a state function
E) energy
12) A chemical reaction that absorbs heat from the surroundings is said to be ______and has a ______ΔH at constant pressure.
A) endothermic, positive
B) endothermic, negative
C) exothermic, negative
D) exothermic, positive
E) exothermic, neutral
13) A chemical reaction that releases heat to the surroundings is said to be ______and has a ______ΔH at constant pressure.
A) endothermic, positive
B) endothermic, negative
C) exothermic, negative
D) exothermic, positive
E) exothermic, neutral
14) The reaction
4Al (s) + 3O2 (g) → 2 Al2O3 (s) ΔH° = -3351 kJ
is ______, and therefore heat is ______by the reaction.
A) endothermic, released
B) endothermic, absorbed
C) exothermic, released
D) exothermic, absorbed
E) thermoneutral, neither released nor absorbed
15) Under what condition(s) is the enthalpy change of a process equal to the amount of heat transferred into or out of the system?
(a) temperature is constant
(b) pressure is constant
(c) volume is constant
A) a only
B) b only
C) c only
D) a and b
E) b and c
16) The units of of heat capacity are ______.
A) K/J or °C/J
B) J/K or J/°C
C) J/g-K or J/g-°C
D) J/mol
E) g-K/J or g-°C/J
17) The units of of specific heat are ______.
A) K/J or °C/J
B) J/K or J/°C
C) J/g-K or J/g-°C
D) J/mol
E) g-K/J or g-°C/J
18) A sample of calcium carbonate [CaCO3 (s)] absorbs 45.5 J of heat, upon which the temperature of the sample increases from 21.1 °C to 28.5 °C. If the specific heat of calcium carbonate is 0.82 J/g-K, what is the mass (in grams) of the sample?
A) 3.7
B) 5.0
C) 7.5
D) 410
E) 5.0 x 103
19) The temperature of a 12.58 g sample of calcium carbonate [CaCO3 (s)] increases from 23.6 °C to 38.2 °C. If the specific heat of calcium carbonate is 0.82 J/g-K, how many joules of heat are absorbed?
A) 0.82
B) 5.0
C) 7.5
D) 410
E) 151
20) An 8.29 g sample of calcium carbonate [CaCO3 (s)] absorbs 50.3 J of heat, upon which the temperature of the sample increases from 21.1 °C to 28.5 °C. What is the specific heat of calcium carbonate?
A) .63
B) .82
C) 1.1
D) 2.2
E) 4.2
21) A 22.44 g sample of iron absorbs 180.8 J of heat, upon which the temperature of the sample increases from 21.1 °C to 39.0 °C. What is the specific heat of iron?
A) 0.140
B) 0.450
C) 0.820
D) 0.840
E) 0.900
22) For which one of the following reactions is ΔH°rxn equal to the heat of formation of the product?
A) N2 (g) + 3H2 (g) → 2NH3 (g)
B) (1/2) N2 (g) + O2 (g) → NO2 (g)
C) 6C (s) + 6H (g) → C6H6 (l)
D) P (g) + 4H (g) + Br (g) → PH4Br (l)
E) 12C (g) + 11H2 (g) + 11O (g) → C6H22O11 (g)
23) Of the following, ΔHf° is not zero for ______.
A) O2 (g)
B) C (graphite)
C) N2 (g)
D) F2 (s)
E) Cl2 (g)
24) Of the following, ΔHf° is not zero for ______.
A) Sc (g)
B) Si (s)
C) P4 (s, white)
D) Br2 (l)
E) Ca (s)
25) Consider the following two reactions:
A → 2B ΔH°rxn = 456.7 kJ/mol
A → C ΔH°rxn = -22.1kJ/mol
Determine the enthalpy change for the process:
2B → C
A) -478.8 kJ/mol
B) -434.6 kJ/mol
C) 434.6 kJ/mol
D) 478.8 kJ/mol
E) More information is needed to solve the problem.
26) In the reaction below, ΔHf° is zero for ______.
Ni (s) + 2CO (g) + 2PF3 (g) → Ni(CO)2 (PF3)2 (l)
A) Ni (s)
B) CO (g)
C) PF3 (g)
D) Ni(CO)2(PF3)2 (l)
E) both CO (g) and PF3 (g)
27) For which one of the following reactions is the value of ΔH°rxn equal to ΔHf° for the product?
A) 2Ca (s) + O2 (g) → 2CaO (s)
B) C2H2 (g) + H2 (g) → C2H4 (g)
C) 2C (graphite) + O2 (g) → 2CO (g)
D) 3Mg (s) + N2 (g) → Mg3N2 (s)
E) C (diamond) + O2 (g) → CO2 (g)
28) For which one of the following reactions is the value of ΔH°rxn equal to ΔHf° for the product?
A) 2 C (s, graphite) + 2 H2 (g) → C2H4 (g)
B) N2 (g) + O2 (g) → 2 NO (g)
C) 2 H2 (g) + O2 (g) → 2 H2O (l)
D) 2 H2 (g) + O2 (g) → 2 H2O (g)
E) H2O (l) + 1/2 O2 (g) → H2O2 (l)
29) For which one of the following reactions is the value of ΔH°rxn equal to ΔH°f for the product?
A) H2O (l) + 1/2 O2 (g) → H2 O2 (l)
B) N2 (g) + O2 (g) → 2NO (g)
C) 2H2 (g) + O2 (g) → 2H2O (l)
D) 2H2 (g) + O2 (g) → 2H2O (g)
E) none of the above
30) For which one of the following reactions is the value of ΔH°rxn equal to ΔH°f for the product?
A) H2 (g) + 1/2 O2 (g) → H2O (l)
B) H2 (g) + O2 (g) → H2O2 (l)
C) 2 C (s, graphite) + 2 H2 (g) → C2H4 (g)
D) 1/2 N2 (g) + O2 (g) → NO2 (g)
E) all of the above
31) The energy released by combustion of 1 g of a substance is called the ______of the substance.
A) specific heat
B) fuel value
C) nutritional calorie content
D) heat capacity
E) enthalpy
32) The ΔE of a system that releases 12.4 J of heat and does 4.2 J of work on the surroundings is ______J.
A) 16.6
B) 12.4
C) 4.2
D) -16.6
E) -8.2
33) The ΔE of a system that absorbs 12.4 J of heat and does 4.2 J of work on the surroundings is ______J.
A) 16.6
B) 12.4
C) 4.2
D) -16.6
E) 8.2
34) The value of ΔH° for the reaction below is -72 kJ. ______kJ of heat are released when 80.9 grams of HBr is formed in this reaction.
H2 (g) + Br2 (g) → 2HBr (g)
A) 144
B) 72
C) 0.44
D) 36
E) -72
35) The value of ΔH° for the reaction below is -790 kJ. The enthalpy change accompanying the reaction of 0.95 g of S is ______kJ.
2S (s) + 3O2 (g) → 2SO3 (g)
A) 23
B) -23
C) -12
D) 12
E) -790
36) The value of ΔH° for the reaction below is -1107 kJ:
2Ba (s) + O2 (g) → 2BaO (s)
How many kJ of heat are released when 5.75 g of Ba (s) reacts completely with oxygen to form BaO (s)?
A) 96.3
B) 26.3
C) 46.4
D) 23.2
E) 193
37) The molar heat capacity of a compound with the formula C2H6SO is 88.0 J/mol-K. The specific heat of this substance is ______J/g-K.
A) 88.0
B) 1.13
C) 4.89
D) 6.88 ×
E) -88.0
38) ΔH for the reaction IF5 (g) → IF3 (g) + F2 (g) is ______kJ, give the data below.
IF (g) + F2 (g) → IF3 (g) ΔH = -390 kJ
IF (g) + 2 F2 (g) → IF5 (g) ΔH = -745 kJ
A) +355
B) -1135
C) +1135
D) +35
E) -35
39) Given the following reactions
Fe2O3 (s) + 3CO (s) → 2Fe (s) + 3CO2 (g) ΔH = -28.0 kJ
3Fe (s) + 4CO2 (s) → 4CO (g) + Fe3O4 (s) ΔH = +12.5 kJ
the enthalpy of the reaction of Fe2O3 with CO 3 Fe2O3 (s) + CO (g) → CO2 (g) + 2 Fe3O4 (s) is ______kJ.
A) -59.0
B) 40.5
C) -15.5
D) -109
E) +109
40) Given the data in the table below, ΔH°rxn for the reaction 3NO2 (g) + H2O (l) → 2HNO3 (aq) + NO (g) is ______kJ.
A) 64
B) 140
C) -140
D) -508
E) -64
Chapter 6 Electronic Structure of Atoms
1) Which one of the following is correct?
A) ν + λ = c
B) ν ÷ λ = c
C) ν = cλ
D) λ = c ν
E) νλ = c
2) The wavelength of light emitted from a traffic light having a frequency of 5.75 × 1014 Hz is ______.
A) 702 nm
B) 641 nm
C) 674 nm
D) 522 nm
E) 583 nm
3) Of the following, ______radiation has the shortest wavelength.
A) X-ray
B) radio
C) microwave
D) ultraviolet
E) infrared
4) All of the orbitals in a given electron shell have the same value of the ______quantum number.
A) principal
B) angular momentum
C) magnetic
D) spin
E) psi
5) All of the orbitals in a given subshell have the same value of the ______quantum number.
A) principal
B) angular momentum
C) magnetic
D) A and B
E) B and C
6) Which of the subshells below do not exist due to the constraints upon the angular momentum quantum number?
A) 4f
B) 4d
C) 4p
D) 4s
E) none of the above
7) Which one of the following is an incorrect subshell notation?
A) 4f
B) 2d
C) 3s
D) 2p
E) 3d
8) Which one of the quantum numbers does not result from the solution of the Schrodinger equation?
A) principal
B) azimuthal
C) magnetic
D) spin
E) angular momentum
9) At maximum, an f-subshell can hold ______electrons, a d-subshell can hold ______electrons, and a p-subshell can hold ______electrons.
A) 14, 10, 6
B) 2, 8, 18
C) 14, 8, 2
D) 2, 12, 21
E) 2, 6, 10
10) If an electron has a principal quantum number (n) of 3 and an angular momentum quantum number (l) of 2, the subshell designation is ______.
A) 3p
B) 3d
C) 4s
D) 4p
E) 4d
11) Which one of the following represents an acceptable set of quantum numbers for an electron in an atom? (arranged as n, l, ml, and ms)
A) 2, 2, -1, -1/2
B) 1, 0, 0, 1/2
C) 3, 3, 3, 1/2
D) 5, 4,- 5, 1/2
E) 3, 3, 3, -1/2
12) Which one of the following represents an acceptable possible set of quantum numbers (in the order n, l, ml, ms) for an electron in an atom?
A) 2, 1, -1, 1/2
B) 2, 1, 0, 0
C) 2, 2, 0, 1/2
D) 2, 0, 1, -1/2
E) 2, 0, 2, +1/2
13) Which one of the following represents an impossible set of quantum numbers for an electron in an atom? (arranged as n, l, ml, and ms)
A) 2, 1, -1, -1/2
B) 1, 0, 0, 1/2
C) 3, 3, 3, 1/2
D) 5, 4, - 3, 1/2
E) 5, 4, -3, -1/2
14) Which electron configuration represents a violation of the Pauli exclusion principle?
A)
B)
C)
D)
E)
15) Which electron configuration represents a violation of the Pauli exclusion principle?