Torr and the solubility of mgf 2 at 20 c is 8 mg per

17 . 54 Torr and the solubility of MgF
2
at 20
◦
C
is 8 mg per 100 g of water.
1. 24.81 Torr
2. 15.02 Torr
3. 17.54 Torr correct
4. None of these
5. 21.06 Torr
6. 19.84 Torr

Yoon, Seong Meen – Exam 1 – Due: Sep 18 2007, 3:00 pm – Inst: James Holcombe 7
018 (part 1 of 1) 10 points
Calculate the number of moles of oxygen that
will dissolve in 45 L of water at 20
◦
C if the par-
tial pressure of oxygen is 0.21 atm. Henry’s
constant for oxygen is 0.0013
mol
L · atm
.
In a closed vessel containing water the pres-
sure is 18 torr. If we add more water to the
vessel, the pressure
Which of the following is true if the distil-
late is collected from a distillation apparatus
while the solution boils?
1. 713 torr
2. 504 torr correct
3. 112 torr
4. 256 torr
5. 52 torr
Explanation:
021 (part 1 of 1) 10 points
Consider the temperature composition dia-
gram of a binary mixture of A and B which
forms a minimum boiling azeotrope: Initially
X
A
= 0 . 6.
0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0
0
20
40
60
80
100
120
140
X
A
boiling temperature (
◦
C)
1. X
A
in the beaker will remain the same.
2. X
A
in the beaker will approach 0.
3. X
A
in the beaker will approach 1.
4. X
A
in the beaker will approach 0.3. cor-
rect
Explanation:
022 (part 1 of 1) 10 points
Mixing 17.6 kg of ethylene glycol (commercial
antifreeze, C
2
H
6
O
2
) with 6.00 gal of water
lowers the freezing point to - 10 . 0
◦
F. Suppose
you wanted to accomplish the same thing with
sugar (sucrose, C
12
H
22
O
11
) instead of ethy-
lene glycol. How many kilograms of sucrose
would you use? 1 gallon = 3.785 liters. K
f
for
water = 1 . 86
◦
C/m.
1. 3.09 kg
2. 97.1 kg correct

Yoon, Seong Meen – Exam 1 – Due: Sep 18 2007, 3:00 pm – Inst: James Holcombe 8
3. 4 . 68 × 10
- 3
kg
4. 17.6 kg
5. 6019 kg
Explanation:
023 (part 1 of 1) 10 points
Several interesting observations from the
world around you are listed below. Which
of these is NOT explained by a colligative
property?