CHEMISTRY 1056 FINAL
This is a sample final exam. You will take the ACS standardized first semester general chemistry final
which has a total of 70 questions.
The exam consists of 30, five point multiple choice questions. There is a periodic table, molecular
geometries chart and some useful equations at the end of this exam.
1.
2.
3.
How many protons, neutrons, and electrons are there, respectively in 69Se2- ?
a.
34, 35, 34
b.
35, 34, 36
c.
34, 34, 36
d.
34, 35, 36
e.
36, 35, 34
What is the most likely formula for the compound that would form between gallium and oxygen?
a.
GaO
b.
GaO2
c.
GaO3
d.
Ga3O2
e.
Ga2O3
The best name for Cr (SO4)3 is:
a.
chromium sulfate
b.
chromium trisulfite
c.
chromium (VI) sulfite
d.
chromium (VI) sulfate
e.
chromium trisulfate
1
4.
5.
6.
Calculate the empirical formula of a compound which is 51.40% carbon, 8.63% hydrogen, and
39.97% nitrogen.
a.
C5H8N2
b.
C4H5N2
c.
C3H5N
d.
C4H4N2
e.
C3H6N2
How many grams of NO2 contain the same number of molecules as 5.00g of H2O?
a.
12.8g
b.
2.77g
c.
5.00g
d.
0.391g
e.
1.96g
In balancing the equation,
____ C + _____ SO2 → ____ CS2 + ____CO
the most correct set of stoichiometric coefficients for the balanced equation is given by:
7.
a.
2, 1, 1, 2
b.
5, 2, 3, 2
c.
4, 2, 1, 4
d.
3, 3, 1, 2
e.
5, 2, 1, 4
For the reaction of 15.0 g of magnesium and 5.00 g of nitrogen, according to the equation below,
which statement is true?
3 Mg + N2 → Mg3N2
a.
magnesium is the limiting reagent
b.
Nitrogen is the limiting reagent
c.
20.0 g of Mg3N2 is produced.
d.
15.0 g of Mg3N2 is produced.
e.
There is no limiting reagent.
2
8.
When the following reagents are mixed:
1)
H2SO3(aq) + KOH(aq)
→
2)
NaHCO3(s) + HCl(aq)
→
3)
Pb(NO3)2(aq) + NH4I(aq) →
4)
NaCl(aq) + Ni(NO3)2(aq) →
which will show evidence of reaction?
a.
1, 3
b.
1, 4
c.
1, 2
d.
1, 2, 3
e.
1, 2, 3, 4
9.
Which of the following substances would exhibit dipole-dipole intermolecular forces?
b. Cl2
c. N2
d. NCl3
e. CH4
a. CCl4
10.
Which of the following would probably have the lowest boiling point?
a. CH4
11.
12.
13.
b.
SiH4
c. PH3
d. AsH3
e. NH3
Which set of quantum numbers is not possible:
a.
n = 1, l = 0, ml = 0, ms = +1/2
b.
n = 2, l = 0, ml = 0, ms = -1/2
c.
n = 2, l = 1, ml = 0, ms = +1/2
d.
n = 3, l = 3, ml = -1, ms = +1/2
e.
n = 4, l = 3, ml = +2, ms = -1/2
Which transition of an electron from one level to another in a hydrogen atom would emit a photon
(particle of light) with the shortest wavelength?
a.
n=3 → n=4
b.
n=3 → n=2
c.
n=4 → n=1
d.
n=1 → n=4
e.
n=2 → n=1
The electron configuration for Bi3+ is:
3
14.
15.
16.
17.
a.
[Xe] 6s2 4f14 5d10 6p2
b.
[Xe] 6s2 4f14 5d10 6p1
c.
[Xe] 6s2 4f14 5d10
d.
[Xe] 4f14 5d106s1
e.
[Xe] 6s2 5d10
Based on a molecular orbital diagram for the compound C2, the molecule is __________ and has a
bond order of ________________.
a.
paramagnetic; 2.
b.
diamagnetic; 2.5.
c.
paramagnetic; 2.5.
d.
diamagnetic; 2.
Which one of the following elements is the most electronegative?
a.
Rb
b.
Ga
c.
Se
d.
Cl
e.
C
Element M reacts with oxygen to form an oxide with the formula MO. When MO is dissolved in
water, the resulting solution is basic. Element M is:
a.
K
b.
Si
c.
Ga
d.
Ca
e.
P
Which one of the following will have the strongest carbon oxygen bond?
a.
CO32—
b.
c.
CO
d.
CO2
O
C
H3 C
4
CH3
18.
19.
The molecular geometry for SeO42— is:
a.
tetrahedral
b.
trigonal bipyramidal
c.
see saw
d.
square pyramidal
e.
octahedral
Liquids with a high surface tension tend to have
a.
b.
c.
d.
e.
20.
21.
strong intermolecular forces.
strong adhesive forces.
strong intramolecular forces.
weak cohesive forces.
no cohesive forces.
One principle of the Kinetic-Molecular Theory of gases is that:
a.
the particles of a gases are always stationary unless struck by some other moving object
b.
the average kinetic energy of gas particles has no relationship to the temperature of the
gaseous mixture.
c.
gases consist of particles whose separation is much greater than the size of the particles
themselves
d.
all collisions between gas particles and container walls result in significant losses of energy
by the particles.
Non-ideal behavior for a gas is most likely to be observed under conditions of:
a. standard temperature and pressure
b. low temperature and high pressure
c. low temperature and low pressure
d. high temperature and high pressure
e. high temperature and low pressure
5
22.
23.
What is the molar mass of a gas which has a density of 1.30 g/L measured at 27.0ºC and 0.400 atm
a. 38.0 g/mol
b. 48.0 g/mol
d. 80.1 g/mol
e. 97.5 g/mol
c. 61.5 g/mol
Rank 355 torr, 0.524 atm, and 49.8 kPa in order of increasing pressure.
a. 355 torr < 0.524 atm < 49.8 kPa
b. 49.8 kPa < 0.524 atm < 355 torr
c. 0.524 atm < 49.8 kPa < 355 torr
d. 355 torr < 49.8 kPa < 0.524 atm
e. 49.8 kPa < 355 torr < 0.524 atm
24.
A sample of hydrogen gas is placed in a U-tube apparatus. The mercury column reaches 525 mm
Hg in the closed tube and 190 mm Hg in the open tube. If the atmospheric pressure is 727 mm Hg,
what is the pressure of the hydrogen in the bulb:
a.
1062 mm Hg
b.
392 mm Hg
c.
525 mm Hg
d.
335 mm Hg
e.
202 mm Hg
6
25.
26.
The pressure and temperature of an ideal gas are both decreased by one-half. The volume of this
ideal gas
a.
is quartered.
b.
is halved.
c.
remains the same.
d.
is doubled.
e.
is quadrupled.
Which of the following gases has the greatest density at 273.15 K and 760 mm Hg?
b. O2
a. N2
27.
28.
29.
c. F2
d. Ne
e. CO
A flask contains a mixture of two gases, A and B, at a total pressure of 4.0 atm. The partial
pressure of gas A in the flask is 1.52 atm. What is the mole fraction of gas B in the flask?
a.
0.25
b.
0.33
c.
0.38
d.
0.62
Which of the following gases effuses at the highest rate:
a.
N2
b.
O2
c.
CO2
d.
Ar
e.
H2O
What are standard temperature and pressure conditions for gases
a. 0.0ºC and 0 mm Hg
b. 0 K and 1 atm
c. –273.15 ΕC and 760 mm Hg
d. 0 ºC and 760 torr
e. 0ºC and 1 bar
7
30.
31.
32.
A sample of helium gas was found to diffuse at a rate equal to 4 times that of an unknown gas. What
is the molecular weight of the unknown gas?
a.
2 g/mole
b.
32 g/mole
c.
16 g/mole
d.
64 g/mole
(2 points) Energy is defined as the capacity to ___________ or to transfer __________.
a. do work, heat
b. transmit chaos, mass
c. split freons, moles
d. energize, ammonia
(2 points) The potential energy of an object is ________________________.
a. dependent on how the object got that potential energy.
b. dependent on the heat transferred
c. independent of the path used to arrive at that potential energy
d. equal to the kinetic energy of the object
33.
(2 points) Propane is a(n) _______________ which is a type of _____________.
a. alkene, fire suppressant
b. alkane, hydrocarbon
c. alkane, unsaturated hydrocarbon c. cyclo-hexane, hydrocarbon
34.
(4 points) Use bond enthalpies (see table at end of exam) to estimate the enthalpy associated with the
combustion of one mole of n-propanol (CH3(CH2)2OH ) at standard conditions. (Hint: make sure the
reaction is balanced.)
____ CH3(CH2)2OH + ____ O2 Æ ____ CO2 + ____ H2O
a. +2.95E3
b. –1.52E3
c. +7.48E3
8
d. –3.04E3
35.
(4 points) Calculate the enthalpy change at standard conditions for the reaction:
HgCl2(s) + Hg(l) → Hg2Cl2(s)
using the following thermodynamic data:
2 Hg(l) + Cl2(g) → Hg2Cl2(s)
ΔHo = –224.0 kJ/mol
Hg(l) + Cl2(g) → HgCl2(s)
ΔH o= –265.2 kJ/mol
a. –112.0
36.
40.
b. 0.261
c. 31.9
d. 1.03E7
b. negative
c. either; depends on the reaction
(2 points) Sublimation is a(n) _____________ process.
a. exothermic
39.
d. –489.2
The sign of the heat energy transfer during a combustion reaction will be _________.
a. positive
38.
c. –41.2
(4 points) Calculate the heat capacity of a calorimeter (kJ/oC) if the combustion of 4.380 g of benzoic
acid led to a temperature increase of 16.761°C. [Molar mass benzoic acid = 122.12; ΔH combustion
for benzoic acid = 3.22E3 kJ/mol]
a. 6.89
37.
b. +41.2
b. random
c. nuclear
d. endothermic
(3 points) The repulsion between electrons in an atom is an example of ______________.
a. potential energy
b. kinetic energy
c. translational energy
d. rotational energy
(4 points) How much PΔV work does a gas system do on its surroundings at a constant pressure of
2.55 atm if the volume of gas increases from 275 mL to 805 mL?
Express your answer in joules
(J).
a. 7.30E-3
b. 6.89E4
c. 1.37E2
9
d. 1.45E-5
41.
(2 points) Calculate ΔE for the combustion of a gas that releases 180. kJ of energy to its surroundings
and does 37.3 kJ of work on its surroundings.
a. +217
42.
43.
45.
c. 4.82
d. –217
(2 points) The specific heat of a material will have the general units of ____________.
a. mass/(energy⋅temperature)
b. temperature/(mass⋅energy)
c. energy/(mass⋅power)
d. energy/(mass⋅temperature)
(4 points) Calculate the specific heat of gold (Au) if a 22.3 gram sample of the metal causes a 8.1 K
change in temperature to its surroundings and is associated with a 23.1 Joule energy transfer.
a. 0.13
44.
b. -143
b. 7.8
c. 64
d. 0.96
e. 1.0
(2 points) Heat transfer at constant pressure is referred to as _________________.
a. entropy
b. endothermic exchange
c. exothermic exchange
d. enthalpy
(4 points) What is the sign and amount of heat (kJ) associated with the following process?
H2O (15.0 g, liq., 57.2 oC) Æ H2O (15.0 g, s, -15.0 oC)
[ΔH(fusion, H2O) = 6.01 kJ/mol; ΔH(vaporization, H2O) = 40.67 kJ/mol; Cp(s, H2O) = 37.1 J/mol⋅K;
Cp(l, H2O) = 75.37 J/mol⋅K; Cp(g, H2O) = 43.1 J/mol⋅K]
a. 7.05
b. –10.2
c. 7.88
d. –8.22
10
e. –9.05
46.
(4 points) What is the final thermal equilibrium temperature (oC) of the mixture when 150. g of Cu at
90.0 oC is added to 150.g of H2O at 25.0°C? (Assume that no heat is lost to the surroundings.)
[Specific Heat: Cu = 0.385 J/g⋅K ; H2O = 4.184 J/g⋅K]
a. 27.3
b. 30.5
c. 44.1
d. 22.7
e. 77.4
47.
The partial pressure of O2 in your lungs varies from 25 mm Hg to 40 mm of Hg. How much O2 can
dissolve in water at 25° C if the partial pressure of O2 is 30 mm of Hg.
[kH (O2/water, 25 °C) = 1.66⋅10−6 M/mm Hg]
48.
If you dissolve 10.0 g of sugar (C12H22O11, formula mass=342.3) into 225 mL of water (formula
mass= 18.015) and then warm the water to 60 ºC, what is the vapor pressure of the water over this
solution? The vapor pressure of pure water at 60 ºC is 149.4 mm of Hg.
49.
The Equilibrium Vapor Pressure exerted by a substance is ______________.
a.
b.
c.
d.
equal to the rate of sublimation for a(n) exothermic reaction
the pressure of the vapor when the rates of evaporation and condensation are equal
the liquid temperature at the normal boiling point temperature
only determined at the critical point temperature
11
50.
This question refers to the following phase diagram.
a•
c
A
b•
d
a.
Describe phase(s) is/are present at point “a”?
b.
Describe what phase(s) is/are present at point “b”.
c.
Describe what changes take place as you travel along the line segment going from point “c”
to point “d”.
d.
Is the solid form of this material more or less dense than the liquid form? Explain!
51.
Calculate the molality of a 7.80% by weight glucose (C6H12O6, formula mass=180.2) in water
solution.
52.
Calculate the weight percent of NiCl2 in a 1.34 molar NiCl2 (formula mass=129.6) solution that has a
density of 1.12 g/cm3.
12
53.
You dissolve an unknown quantity of phenanthrene (C14H10, formula mass=178.23) in 50.0 g of
benzene. The boiling point of the solution is 81.05 ΕC. What mass of phenathrene must have been
dissolved in the benzene? [Benzene B.P. (1 atm) = 80.10 °C; Kb (benzene) = 2.53 °C/m]
54.
An aqueous solution of 1.00 g of bovine serum albumin (BSA) per liter has an osmotic pressure of
3.1 mm Hg at 25.0 °C. Calculate the molar mass of BSA. (BSA is a protein and is not ionized in
solution)
55.
A colloidal dispersion has ________________________.
a. particles in suspension that are much larger than individual ions or molecules
b. molecules dissolved in a very viscous liquid that keep them suspended
c. solute particles in a homogeneous solution
d. two immiscible layers separated by density differences
56.
A protozoan, (single celled animal) that normally lives in the ocean is placed in fresh water. Will it
shrivel or burst? Explain!
57.
The half-life of a reaction is the ___________________________.
a. time necessary for one-half of the initial reacting material to be used up
b. concentration of reactant remaining when the system reaches equilibrium.
c. Sum of the rate constant plus 0.693
d. Time necessary for the concentration of products to equal that of the reactants
58.
Calculate the binding energy of the potassium-39 nucleus. The exact mass of the 39K atom is
38.9637074 amu.
a. 5.192E-11 J
b. 5.867E-9 J
c. 5.347E-11 J
13
d. 5.815E-9 J
59.
Which of the choices below best completes the following nuclear reaction?
________ + 1H Æ 67Ga + 2 1n
a. Zinc-68
60.
61.
62.
c. copper-68
d. gallium-69
Which of the choices below best completes the following nuclear reaction?
116
In Æ ________ + β
a.
117
Cd
b.
117
Ag
c. 118In
d.
116
Sn
Which of the choices below best completes the following nuclear reaction?
146
Pm Æ ________ + α
a.
142
Ce
b.
142
c. 140Ce
Pr
d.
144
Sm
The EPA allowed level of radon in drinking water is 300. pCi per liter of water. This corresponds to
_______ disintegrations per second.
a. 11
63.
b. Germanium-69
b. 1.1E13
c. 9.0E-14
d. 8.1E-9
An isotope is likely to undergo β-decay if it has _________________.
a. a higher proton to neutron ratio than the stable isotopes of that element
b. a higher proton to electron ratio than the stable isotopes of that element
c. an equal number of protons and neutrons
d. a higher neutron to proton ratio than the stable isotopes of that element
64.
For gamma radiation 1 rad equals __________.
a. 1 rem
65.
b. 3.7E10 dps
c. 500 J kg-1
d. 0.01 RBE
Some workers responding to the explosion at the Chernobyl nuclear power plant were exposed to 375
rem of radiation, resulting in death for many of them. If the exposure was primarily in the form of γ rays with an energy of 2.85E-14 J photon-1 and an RBE of 1, how many γ -ray photons did an 175 lb
person absorb?
a. 9.8E-18
b. 2.3E18
c. 1.3E16
14
d. 1.0E16
66.
Strontium-90 is a particularly hazardous radioactive isotope in the environment since it will
substitute for calcium in bones and teeth. Predict its decay process.
a. alpha emission
b. beta emission
c. positron emission
d. neutron capture
e. electron capture.
Some useful constants and formulas:
speed of light = c = 2.998 10+8 m/sec
Planck's constant = h = 6.626 10-34 Joule sec
E = hν
Rydberg constant = 1.0968•10+7 m—1
RH = 2.18•10 l8 J
En = (1.0968•10+7 m Γ1) h c / n2 = (2.18•10 18 J) / n2
E = RH (1/ni2 - 1/nf2)
R = 0.082057 L•atm / mole•K
1 atm = 14.70 psia = 1.01325 bar = 101.3 kPa
Possible Molecular Geometries
15
16