CHEMISTRY 1710 - Practice Exam #4
This is a multiple choice exam. Choose the BEST answer from the choices
which are given and write the letter for your choice in the space provided.
_____ 1. Which statement is TRUE about kinetic molecular theory?
A) A single particle does not move in a straight line.
B) The size of the particle is large compared to the volume.
C) The collisions of particles with one another are completely elastic.
D) The average kinetic energy of a particle is not proportional to the temperature
_____ 2. Which of the following statements is TRUE?
A) Particles of different masses have the same average speed at a given temperature.
B) The larger a molecule, the faster it will effuse.
C) At very high pressures, a gas will occupy a larger volume than predicted by the ideal
gas law.
D) For a given gas, the lower the temperature, the faster it will effuse.
_____ 3. Which of the following signs on q and w represent a system that is doing work on the
surroundings, as well as gaining heat from the surroundings?
A) q = +, w = C) q = +, w = +
B) q = -, w = +
D) q = -, w = -
_____ 4. Calculate the change internal energy (ΔE) for a system that is giving off 45.0 kJ of heat and is
performing 855 J of work on the surroundings.
A) 44.1 kJ
C) -45.9 kJ
B) -44.1 kJ
D) 9.00 x 102 kJ
_____ 5. Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 40 L
against a constant external pressure of 1.5 atm. 101.3 L · atm = 101 J
A) -6.1 kJ
B) -3.8 kJ
C) +3.8 kJ
D) +6.1 kJ
_____ 6. A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C,
determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J/g°C.
A) 1.51 kg
C) 1.26 kg
B) 6.62 kg
D) 7.94 kg
_____ 7. The specific heat capacity of liquid water is 4.18 J/g-K. How many joules of heat are needed
to raise the temperature of 5.00 g of water from 25.1°C to 65.3°C?
A) 48.1 J
B) 840 J
C) 1.89 × 103 J
D) 2.08 × 10-2 J
_____ 8. Which of the following substances (with specific heat capacity provided) would show the
greatest temperature change upon absorbing 100.0 J of heat?
A) 10.0 g Fe, CFe = 0.449 J/g°C
B) 10.0 g H2O, CH2O = 4.18 J/g°C
C) 10.0 g ethanol, Cethanol = 2.42 J/g°C
D) 10.0 g Au, CAu = 0.128 J/g°C
______ 9. A 6.55 g sample of aniline (C6H5NH2, molar mass = 93.13 g/mol) was combusted in a
bomb calorimeter. If the temperature rose by 32.9°C, use the information below to determine the heat
capacity of the calorimeter.
4 C6H5NH2(l) + 35 O2(g) → 24 CO2(g) + 14 H2O(g) + 4 NO2(g)
ΔH°rxn = -1.28 x 104 kJ
A) 97.3 kJ/°C
B) 38.9 kJ/°C
C) 5.94 kJ/°C
D) 6.84 kJ/°C
_____ 10. How much energy is evolved during the reaction of 48.7 g of Al, according to the
reaction below? Assume that there is excess Fe2O3.
Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s) ΔH°rxn = -852 kJ
A) 415 kJ
B) 769 kJ
C) 241 kJ
D) 130 kJ
_____11. Use the standard reaction enthalpies given below to determine ΔH°rxn for the
following reaction:
2 NO(g) + O2(g) → 2 NO2(g)
ΔH°rxn = ?
Given:
N2(g) + O2(g) → 2 NO(g)
ΔH°rxn = +183 kJ
1/2 N2(g) + O2(g) → NO2(g) ΔH°rxn = +33 kJ
A) -150. kJ
B) -117 kJ
C) -333 kJ
D) +115 kJ
_____12. Choose the reaction that illustrates ΔH°f for NaHCO3.
A) Na(s) + H2(g) + C(s) + O2(g) → NaHCO3 (s)
B) Na+(aq) + HCO3 -1 (aq) → NaHCO3 (s)
C) Na+(aq) + H2O (l) + CO2 (g) → NaHCO3 (s)
D) Na(s) + 1/2 H2(g) + C(s) + 3/2 O2(g) → NaHCO3 (s)
_____13. Use the information provided to determine ΔH°rxn for the following
reaction:
ΔH°f (kJ/mol)
CH4(g)
CHCl3(l)
HCl(g)
CH4(g) + 3 Cl2(g) → CHCl3(l) + 3 HCl(g) ΔH°rxn = ?
-75
-134
-92
A) -151 kJ
B) -335 kJ
C) +662 kJ
D) +117 kJ
______14. Which of the following occur as the wavelength of a photon increases?
A) the frequency decreases
B) the energy increases
C) the speed decreases
D) Planck's constant decreases
_____15. Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a
frequency of 6.88 × 1014 Hz.
A) 229 nm
B) 436 nm
C) 206 nm
D) 485 nm
_____16. Calculate the energy of the violet light emitted by a hydrogen atom with a wavelength of
410.1 nm.
A) 4.85 × 10-19 J
B) 2.06 × 10-19 J
C) 1.23 × 10-19 J
D) 8.13 × 10-19 J
_____17. What total energy (in kJ) is contained in 1.0 mol of photons, all with a frequency of 2.75 ×
1014 Hz?
A) 182 kJ
B) 219 kJ
C) 110 kJ
D) 326 kJ
_____18. What are the possible orbitals for n = 3?
A) s, p
C) s
B) s, p, d, f
D) s, p, d
_____19. Each of the following sets of quantum numbers is supposed to specify an orbital.
Which of the following sets of quantum numbers contains an error?
A) n = 2, l = 1 , ml = -1
C) n = 3, l =3 , ml = -2
B) n = 4, l = 2, ml =0
D) n = 1, l = 0, ml =0
_____20. Which of the following statements is TRUE?
A) The principal quantum number (n) describes the shape of an orbital.
B) The angular momentum quantum number (l) describes the the size and energy
associated with an orbital.
C) The magnetic quantum number (ml) describes the orientation of the orbital.
D) An orbital is the path that an electron follows during its movement in an atom.
_____21. Calculate the frequency of light associated with the transition from n = 2 to n = 3 in
the hydrogen atom.
A) 2.19 × 1014 s-1
B) 5.59 × 1014 s-1
C) 4.57 × 1014 s-1
D) 1.79 × 1014 s-1
_____22. Which of the following quantum numbers describes the size and energy of an orbital?
A) magnetic quantum number
C) angular momentum quantum number
B) principal quantum number
D) spin quantum number
_____23. Give the set of four quantum numbers that could represent the last electron added
(using the Aufbau principle) to the Cl atom.
A) n = 3, l = 1, ml = 1, ms = +½
B) n = 3, l = 0, ml = 1, ms = -½
C) n = 3, l = 2, ml =1 , ms = +½
D) n = 2, l = 1, ml = 1, ms = -½
_____24. Give the ground state electron configuration for Se.
A) [Ar]4s23d104p4
C) [Ar]4s23d104p6
B) [Ar]4s24d104p4
D) [Ar]4s23d10
_____25. How many electrons are in the outermost shell of the Ga3+ ion in its ground state?
A) 2
B) 3
C) 6
D) 18
_____ 26. Which of the following have their valence electrons in the same primary energy shell?
A) Li, N, F
B) B, Si, As
C) N, As, Bi
D) He, Ne, F
_____ 27. Which of the following have the same number of valence electrons?
A) Rb, Sb, I
B) Ga, Sn, Bi
C) As, Sb, Bi
D) Ar, Kr, Br
_____ 28. Place the following elements in order of decreasing atomic radius.
Xe
Rb
Ar
A) Ar > Xe > Rb
C) Ar > Rb > Xe
B) Xe > Rb > Ar
D) Rb > Xe > Ar
_____ 29. An element that has the valence electron configuration 6s26p6 belongs to which period and
group?
A) period 6; group 6A
B) period 6; group 8A
C) period 7; group 6A
D) period 7; group 8A
_____ 30. Choose the statement that is TRUE.
A) Outer electrons efficiently shield one another from nuclear charge.
B) Core electrons effectively shield outer electrons from nuclear charge.
C) Valence electrons are the most difficult of all electrons to remove.
D) Core electrons are the easiest of all electrons to remove
_____ 31. Choose the diamagnetic species from below.
A) Cr! !
!
B) Br
C) P
D) Sn2⁺
_____ 32. The effective nuclear charge experienced by a valence electron is less than the
actual nuclear charge due to
A) paramagnetism.
B) promotion of core electrons to the valence shell.
C) shielding of valence electrons by core electrons.
D) electron-pair repulsions in the valence shell.
Help equations:
q = m x Cs x ∆T
ΔHºrxn = ΣnpΔHºf (products) - ΣnrΔHºf
(reactants)
ν=c/λ
E=hν
E=hc/λ
λ=h/mν
En = -2.18 x 10-18 J (1/n2)
Δx × Δv ≥ h/4π
(n=1,2,3,...)
Δ En = -2.18 x 10-18 J (1/nf2 - 1/ni2)
n = 1, 2, 3, 4, .......
l = 0, 1, 2, ..., n-1
ml = -l, ..., 0, ..., +l
ms = ±½
R= 0.0821 L-atm mol-1K-1
NA = 6.022 x 1023 mol-1
c = 2.998 x 108 m/sec
0ºC = 273.15 K
h = 6.626 x 10-34 J-s