ACS Gen Chem 2 Final Exam Study Guide.
Where is the hydrophilic (attracted to water) region of the molecule?
(A) Region I
(B) Region 2
(C) Region 3
(D) The three regions are equally hydrophilic
c
Which molecule is most soluble in water?
c
A solution of NaCl in water has a concentration of 20.5% by mass.
What is the mole concentration of the solution?
(A) 0.205 m
(B) 0.258 m
(C) 3.51 m
(D) 4.41
d
What is the mole fraction of water in 200. g of 89% (by mass) ethanol, C2H50H?
(A) 0.11
(B) 0.24
b
A mixture of 100 g of K2Cr207 and 200 g of
water is stirred at 60 °C until no more of the
salt dissolves. The resulting solution is
poured off into a separate beaker, leaving the
undissolved solid behind. The solution is
now cooled to 20 oc_ What mass of KzCr 01 2
crystallizes from the solution during the cooling?
(A) 9g
(B) 18 g
(C) 31g
(D) 62 g
d
Carbonated beverages have a fizz because of gas dissolved in the solution. What increases
the concentration ofgas in a solution?
(A) cooling the solution
(B) heating the solution
(C) increasing the volume of solution
(D) decreasing the volume of solution
a
,When 100. g of an unknown compound was dissolved in 1.00 kg of water, the freezing point
was lowered by 6.36 °C. What is the identity of this unknown compound? (Kr for water=
l.86°C·m-1)
(A) CsCI
(B) KCI
(C) LiF
(D) NaCl
d
Which 0.1 molal aqueous solution will have the lowest freezing point?
(A) Al(NO3)3
(B) CaCl2
(C)C2H5OH
(D) NaCl
a
Which pair of compounds will form hydrogen bonds with one another?
(A) CH4 and H20
(B) CH4 and NH3
(C) HF and CH4
(D) HzO and NH3
d
Which pair of compounds will form hydrogen bonds with one another?
d
What would be expected to be the most soluble in ethanol (CH3CHzOH)?
( A ) CH3CHzCH3
(B)C02
( C ) NH3
c
Which substance is most soluble in water?
(B) ethanol, CH3CHzOH
(C) n-butane, CH3CH2CHzCH3
b
Consider the structure of Vitamin A1 (C2oH3oO). Vitamin A1 should be
(A) insoluble in water and in oiL
(B) less soluble in water than in oiL
(C) equally soluble in water and in oil.
(D) more soluble in water than in oil.
b
The mass percent of acetic acid (CH3COOH) in a bottle ofvinegar is 5.45% in water. What
is the molar concentration of acetic acid in vinegar, assuming the density of vinegar is 1.005
g·mL-1?
,(A) 0.545 M
(B) 0.903 M
(C) 0.908M
(D) 0.912 M
d
A 2SO-mL bottle of a sports drink solution contains 4.SO% by mass of sodium chloride.
What is the molal concentration ofsodium chloride in this bottle of sports drink?
(A) 0.806 m
(B) 0.770 m
(C) 0.180m
a
A 1400 g sample of stream water contains 12.2 ppm of mercury. What is the mass of Hg in
the sample?
(A) 0.1I mg
(B) 2.4mg
(C) 8.7mg
(D) 17mg
d
What mass of water is needed to dissolve 292.5 g ofNaCl to produce a 0.25 m aqueous
solution?
(A) 20 kg
(B) 5.0 kg
(C) 0.80 kg
a
The density of a 3.539 M HN03 aqueous solution is 1.150 g·mL-1 at
20 oc. What is the molal concentration?
(A) 3.077
(B) 3.818
(C)3.946
b
The solubility of a substance is 60 g per I00 mL of water at IS oc. A solution of this
substance is prepared by dissolving 7S g in I 00 mL of water at 7S oc. The solution is then
cooled slowly to IS oc without any solid separating. The solution is
(B) supersaturated at I5 oc.
b
A student mixes 20.0 g of a salt in I00.0 g of water at 20 oc and obtains a homogeneous
solution. Which salt could this be and why?
(A) KCI because it is saturated.
, B) KCl because it is unsaturated.
(D) KN03 because it is unsaturated.
d
The solubility of carbon dioxide in water is very low in air (l.OSx w-s Mat 2S 0 C) because
the partial pressure of carbon dioxide in air is only 0.00030 atm. What partial pressure of
carbon dioxide is needed to dissolve I00.0 mg of carbon dioxide in 1.00 L of water?
(A)0.0649 atm
(B) 2.86 atm
(C) 28.6 atm
(D) 64.9 atm
a
How will you increase the solubility of oxygen in water? The partial pressure of oxygen ( P ,
) is 0.21 atm in air at I atm (Pext).
(A) increase P0 , but keep Pext constant
(B) decrease P0 , but keep Pext constant
(C) increase Pcxt but keep P0 , constant
(D) decrease Pext but keep ~1, constant
a
A 2.50 g sample of naphthalene, C1oHs, was dissolved in 100 g of benzene. What is the
freezing point ofthe benzene solution? The freezing point of pure benzene is S.4S °C; Kr =
S.07 °C·m-1•
(A)-0.989 oc
(B) 0.989 oc
(C) 4.46 oc
(D) 6.44 oc
c
A technician has the measured osmotic pressure of a solution to . determine the molar mass
of a covalent solute. Which other
information would need to be measured in order to determine the molar mass?
I. Temperature
II. Volume of solution
III. Mass of solute
(A) Only I
(B) Only III
(D) I,II,and III
d
A solution was made by adding 800 g of ethanol, C2H50H, to 8.0x10^3g of water. How
much would this lower the freezing point
(A) 3.2oc
Where is the hydrophilic (attracted to water) region of the molecule?
(A) Region I
(B) Region 2
(C) Region 3
(D) The three regions are equally hydrophilic
c
Which molecule is most soluble in water?
c
A solution of NaCl in water has a concentration of 20.5% by mass.
What is the mole concentration of the solution?
(A) 0.205 m
(B) 0.258 m
(C) 3.51 m
(D) 4.41
d
What is the mole fraction of water in 200. g of 89% (by mass) ethanol, C2H50H?
(A) 0.11
(B) 0.24
b
A mixture of 100 g of K2Cr207 and 200 g of
water is stirred at 60 °C until no more of the
salt dissolves. The resulting solution is
poured off into a separate beaker, leaving the
undissolved solid behind. The solution is
now cooled to 20 oc_ What mass of KzCr 01 2
crystallizes from the solution during the cooling?
(A) 9g
(B) 18 g
(C) 31g
(D) 62 g
d
Carbonated beverages have a fizz because of gas dissolved in the solution. What increases
the concentration ofgas in a solution?
(A) cooling the solution
(B) heating the solution
(C) increasing the volume of solution
(D) decreasing the volume of solution
a
,When 100. g of an unknown compound was dissolved in 1.00 kg of water, the freezing point
was lowered by 6.36 °C. What is the identity of this unknown compound? (Kr for water=
l.86°C·m-1)
(A) CsCI
(B) KCI
(C) LiF
(D) NaCl
d
Which 0.1 molal aqueous solution will have the lowest freezing point?
(A) Al(NO3)3
(B) CaCl2
(C)C2H5OH
(D) NaCl
a
Which pair of compounds will form hydrogen bonds with one another?
(A) CH4 and H20
(B) CH4 and NH3
(C) HF and CH4
(D) HzO and NH3
d
Which pair of compounds will form hydrogen bonds with one another?
d
What would be expected to be the most soluble in ethanol (CH3CHzOH)?
( A ) CH3CHzCH3
(B)C02
( C ) NH3
c
Which substance is most soluble in water?
(B) ethanol, CH3CHzOH
(C) n-butane, CH3CH2CHzCH3
b
Consider the structure of Vitamin A1 (C2oH3oO). Vitamin A1 should be
(A) insoluble in water and in oiL
(B) less soluble in water than in oiL
(C) equally soluble in water and in oil.
(D) more soluble in water than in oil.
b
The mass percent of acetic acid (CH3COOH) in a bottle ofvinegar is 5.45% in water. What
is the molar concentration of acetic acid in vinegar, assuming the density of vinegar is 1.005
g·mL-1?
,(A) 0.545 M
(B) 0.903 M
(C) 0.908M
(D) 0.912 M
d
A 2SO-mL bottle of a sports drink solution contains 4.SO% by mass of sodium chloride.
What is the molal concentration ofsodium chloride in this bottle of sports drink?
(A) 0.806 m
(B) 0.770 m
(C) 0.180m
a
A 1400 g sample of stream water contains 12.2 ppm of mercury. What is the mass of Hg in
the sample?
(A) 0.1I mg
(B) 2.4mg
(C) 8.7mg
(D) 17mg
d
What mass of water is needed to dissolve 292.5 g ofNaCl to produce a 0.25 m aqueous
solution?
(A) 20 kg
(B) 5.0 kg
(C) 0.80 kg
a
The density of a 3.539 M HN03 aqueous solution is 1.150 g·mL-1 at
20 oc. What is the molal concentration?
(A) 3.077
(B) 3.818
(C)3.946
b
The solubility of a substance is 60 g per I00 mL of water at IS oc. A solution of this
substance is prepared by dissolving 7S g in I 00 mL of water at 7S oc. The solution is then
cooled slowly to IS oc without any solid separating. The solution is
(B) supersaturated at I5 oc.
b
A student mixes 20.0 g of a salt in I00.0 g of water at 20 oc and obtains a homogeneous
solution. Which salt could this be and why?
(A) KCI because it is saturated.
, B) KCl because it is unsaturated.
(D) KN03 because it is unsaturated.
d
The solubility of carbon dioxide in water is very low in air (l.OSx w-s Mat 2S 0 C) because
the partial pressure of carbon dioxide in air is only 0.00030 atm. What partial pressure of
carbon dioxide is needed to dissolve I00.0 mg of carbon dioxide in 1.00 L of water?
(A)0.0649 atm
(B) 2.86 atm
(C) 28.6 atm
(D) 64.9 atm
a
How will you increase the solubility of oxygen in water? The partial pressure of oxygen ( P ,
) is 0.21 atm in air at I atm (Pext).
(A) increase P0 , but keep Pext constant
(B) decrease P0 , but keep Pext constant
(C) increase Pcxt but keep P0 , constant
(D) decrease Pext but keep ~1, constant
a
A 2.50 g sample of naphthalene, C1oHs, was dissolved in 100 g of benzene. What is the
freezing point ofthe benzene solution? The freezing point of pure benzene is S.4S °C; Kr =
S.07 °C·m-1•
(A)-0.989 oc
(B) 0.989 oc
(C) 4.46 oc
(D) 6.44 oc
c
A technician has the measured osmotic pressure of a solution to . determine the molar mass
of a covalent solute. Which other
information would need to be measured in order to determine the molar mass?
I. Temperature
II. Volume of solution
III. Mass of solute
(A) Only I
(B) Only III
(D) I,II,and III
d
A solution was made by adding 800 g of ethanol, C2H50H, to 8.0x10^3g of water. How
much would this lower the freezing point
(A) 3.2oc
