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a. Moles of solute per liter of solution is the definition of
mole fraction molarity molality parts per million
b. Which one of the following does NOT usually increase with temperature?
osmotic pressure solubility of a gas in water
vapor pressure solubility of a salt in water
c. Which one of the following forces is most important for the solubility of octane in hexane?
hydrogen bonding ion-dipole forces dipole-dipole forces London forces
d. If an aqueous solution has a boiling point of 101.
o
C at 1 atm, what is its freezing point?
( for water K f
o
C m
, K
b
o
C m
o
C 3.
o
C - 1.
o
C - 3.
o
C
e. Which one of the following is most likely to be soluble in a nonpolar solvent?
H
2
O CH
3
OH Cl 2
KCl
f. Which one of the following is likely to be most soluble in H 2
O?
CH
3
OH CH
3
CH
2
CH
2
OH I
2
CH
3
CH
2
CH
3
g. Which one of the following will always DECREASE the amount of O 2
dissolved in water?
increasing the temperature and increasing the pressure of O 2
above the water
increasing the temperature and decreasing the pressure of O 2
above the water
decreasing the temperature and increasing the pressure of O 2
above the water
decreasing the temperature and decreasing the pressure of O 2
above the water
h. Which one of the following statements is TRUE?
All salts easily dissolve in water
Energy is always required to break the bonds in an ionic crystal
When NaCl dissolves it breaks down into Na and Cl atoms
Salts dissolve readily in CH 3
CH
2
CH
2
CH
2
CH
2
CH
3
i. A colligative property is a property of a solvent that
depends on the molecular weight of the solvent,
depends on the amount of solute
depends on the total mass of the solvent
depends on the volume of the solution
j. If two salt solutions are separated by a semipermeable membrane there will be a net flow of
solvent from the low concentration solution to the high concentration solution
solute from the high concentration solution to the low concentration solution
solvent from the high concentration solution to the low concentration solution
solute from the low concentration solution to the high concentration solution
k. The vapor pressure of a liquid decreases when
temperature increases
a nonvolatile solute is dissolved
the pressure above the solution is lowered
the liquid is transferred to a smaller container
l. A solution is made by mixing one mole of toluene with one mole of benzene at 25 C. For
pure benzene the vapor pressure is 80 torr and for pure toluene the vapor pressure is 50
torr. The mole fraction of toluene in the vapor above the solution is
greater than 0.5 equal to 0.5 less than 0.
m. Which one of following aqueous solutions will have the lowest freezing point
0.5 m NaCl 0.25 m KCl 0.2 m MgCl 2
0.1 m CoCl 3
n. Which one of the following forces is most important for the high solubility of KCl in water
hydrogen bonding London forces ion-dipole forces dipole-dipole forces
o. The solubility of a gas is water is highest for which conditions of temperature and pressure?
high P, high T high P, low T low P, high T low P, low T
p. Which one of the following is NOT a colligative property?
freezing point depression temperature
osmotic pressure vapor pressure lowering
q. Which one of the following combinations would NOT be likely form a solution
ionic solid and non-polar liquid
ionic solid and polar liquid
polar solid and polar liquid
non-polar solid and non-polar liquid
r. Blood cells have a semipermeable membrane and their fluid contains dissolved ions. When
blood cells are placed in a concentrated salt solution they shrink because
ions pass through the cell membrane by osmosis
water passes through the cell membrane by osmosis
water passes through the cell membrane by reverse osmosis
salt passes through the cell membrane by osmosis
s. Which one of the following is a colloid that has a solid suspended in a liquid?
emulsion sol foam aerosol
t. A soap molecule contains
a polar group at the end of a long polar chain
a nonpolar group at the end of a long polar chain
a nonpolar group at the end of a long nonpolar chain
a polar group at the end of a long nonpolar chain
. Which one of the following statements is TRUE?
A mixture of liquids is always a solution
A colloid is a solution
A solution may have more than one phase
Air is an example of a solution
____________________________________________________________
Circle the member of each of the following pairs that is likely to be more soluble in the indicated
solvent.
CH
3
CH
2
CH
2
OH or Br 2
CH
3
CH
2
CH
2
CH
2
CH
2
OH or CH 3
OH CH
3
OH or I 2
mol
g
0. 372 mol
1000 g
20 g
2 .15 g
unk
CCl 4
CCl 4
unk
_________________________________________________
3 A solution is made by adding 10.0 g of NaCl (FW = 58.4 g mol
to 100.0 g of H 2
O (MW =
18.0 g mol
). The vapor pressure of pure H 2
O is 18 torr at 20 C.
a. Find the vapor pressure of the solution at 20 C.
- 172 mol
5 8.4g mol
1 0.0 g
n
1
NaCl
- 51 mol
18 g mol
100 g
n
1
H 2 O
51 mol 0 .. 172 mol
51 mol
x
H 2 O
P x P 0. 970 1 8.0mmHg 17. 5 mmHg
0
H 2 O H 2 O H 2 O
b. Find the freezing point of this solution. (K f
= 1.86 C/m for water)
- 72 m
kg
mol
72
100 kg
172 mol
molality
T iKm 2 1. 86 Cm 1. 72 m 6. 40 C
o 1 o
f f
freezing point = 0 – T f
o
C
__________________________________________________________
Calculate the osmotic pressure in torr for a 650 mL of an aqueous solution containing 42.0 g of
sucrose. Assume the temperature is 25 C. (MW = 342 g/mol for sucrose)
- 123 mol
342 g mol
- 0 g
1
L
mol
0. 650 L
- 123 mol
M
0. 0821 LatmK mol 298 K 4. 63 atm
L
mol
MRT 0. 189
1 1
__________________________________________________________________________
7 (10) Find the osmotic pressure in torr for a solution made by adding 20.0 g of NaCl (FW 58.44)
to 200 mL of water. Assume the temperature is 20
o
C.
L
mol
0. 200 L
- 342 mol
200 mL
44 g mol
0 g
V
n
M
1
= iMRT
293 K 82. 4 atm
mol K
- 0821 L atm
L
mol
6. 26 10 torr
atm
760 torr
- 4 atm
4
___________________________________________________________________________
Assume that the partial pressure of O 2
above a solution is 150 mm Hg and the partial pressure of
N
2
is 610 mm Hg. For water at 20
o
C, the Henry’s law constant for O 2
is 1.43 x
mol L
atm
and for N 2
is 7.34x
mol L
atm
What is the molarity of O 2
in solution?
What is the mole fraction of O 2
in solution? Assume that the density of water is 1.
g/mL. FW O 2
= 18 g/mol, FW H2O = 18 g/mol.
Is there more N 2
or O 2
dissolved in the water? Show calculations to demonstrate your
conclusion.
___________________________________________________________________________
a. Which one of the following DOES NOT have cis and trans isomers?
2,3-dichloro-2-butene 1,1-dichloro-1-butene
2-chloro-2-butene 1,2-dichloro-propene
b Which one of the following molecules could be used to make a chain growth (addition)
polymer?
methanol propene methyl ethyl ether ethane
c. Which one of the followings statements is FALSE?
Proteins are made up from amino acids linked together by condensation reactions
The genetic code is stored in the sequence of the bases in DNA
The -helix is an important structure for proteins
A nucleotide contains phosphate group, an ether and an organic base
d. Which one of the following compounds is a saturated hydrocarbon?
4-Pentene 2-butyne 3-methyl 2-pentene 2-methylpropane
e. How many isomers are there for the formula C 2
H
2
Cl 2
f. Which one of the following is a polysaccharide that is used to store energy in the human body
fructose starch glucose cellulose
g. Which one of the following is not part of DNA?
phosphate base sugar amino acid
h. Which one of the bonds in the DNA double helix structure are the weakest
the bonds between the bases
the bonds between the phosphate and sugar
the bond between the sugar and the base
the bond between the base and phosphate
i. How many isomers are there for the formula C 3
H
6
Br 2
__________________________________________________________
Draw the structures of the following.
3-pentanol 2-hexanone 2,6-dimethyl-3-heptene
3-methyl butanal 2,2,4-trimethylpentane
C
C
C
C
C
C
C
C C
C
C
C
C
C
C
C C
C C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C C
C C
C
C C
C C
C
C
C
C
C
C
C
C
C
C
C
C
C C
C
1-pentene trans 2-pentene
cis 2-pentene
cyclopentane methyl cyclobutane
ethyl cyclopropane
2-methyl 2 butene
3 methyl 1 butene
2 methyl 1 butene
trans 1,2-dimethyl
cyclopropane
cis 1,2-dimethyl
cyclopropane
1,1-dimethyl
cyclopropane
H
3
C
CH
2
CH
CH
2
CH
3
OH
H
3
C C CH
2
CH
2
CH
2
CH
3
O
H
3
C
C
CH
CH
2
CH
2
CH
CH
3
H
3
C CH 3
C
CH
2
CH
CH
3
CH
3
O
H
H
3
C C CH
2
CH CH
3
CH 3
CH
3
CH 3
- (5 pts) Identify the class (alcohol, alkane, alkene, alkyne, amine, amide, amino acid, aldehyde,
aromatic, carboxylic acid, ether, ester, ketone) that best describes the following molecules. R and
R’ are hydrocarbon groups
alcohol amine aldehyde acid ketone
Identify each of the four following structures as (amino acid, alkane, alkyne, alkene, aromatic,
carbohydrate, dipeptide, dissacharide, nucleotide, tripeptide)
nucleotide carbohydrate
dipeptide amino acid
Consider the molecule shown below. Use asterisks to indicate the chiral carbons.
N
H
N
H
C
O
C
C
O
O
C
H
H
O H
C H
3
C
O H
H
H
C
O H
N
C H
3
Draw the structures for four compounds with the formula C 4
H
8
. Name all compounds. (1 point
per correct structure, 1 point per correct name, 8 points max)
H 2
C
H 2
C CH 2
CH 2
C C
H
CH 3
H
3
C
H
C C
H
CH 3
H
H 3
C
C C
CH 3
CH
3
H
H
trans-2-butene
cis-2-butene
2-methylpropene cyclobutane
