I) will have 1.2 mol of particles because
NaOH completely dissociates in water.
II) will have 1.4 mol of particles because
KCl completely dissociates in water.
III) will have 1.5 mol of particles because
Na
2
CO
3
completely dissociates in water.
IV) will have 1 mol of sugar in solution
because it is soluble but does not dissociate.
The higher the concentration, the greater
the boiling point elevation, so
IV
>
I
>
II
>
III
.
014(part1of3)10.0points
Consider the following pressure diagram for a
binary liquid containing A and B.
clow (twc432) – Homework #2 – holcombe – (51160)501xA80 torr20 torr
If 7 mol of A and 6 mol of B are mixed,what is the vapor pressure of B?
What is the corresponding vapor pressure ofA?
2.36 torr
3.10 torrcorrect4.47 torr
5.80 torrExplanation:
010.54
20 torr10 torr016(part3of3)10.0points
What is the corresponding total vapor pressure?
1.47 torrcorrect2.36 torr3.20 torr4.10 torr5.80 torrExplanation:010.5420 torr47 torr
017
10.0points
WITHDRAWN
018
10.0points
An unknown liquid has a vapor pressure of88 mmHg at 45◦C and a heat of vaporizationof 32 kJ/mol, what is its vapor pressure at55◦C?
clow (twc432) – Homework #2 – holcombe – (51160)
6
1.
156 mmHg
2.
61 mmHg
3.
127 mmHg
correct
4.
89
.
4 mmHg
Explanation:
Use
the
ClausiusClapeyron
Equation.
Here, the only thing we don’t know is
P
2
.
ln
parenleftbigg
P
2
P
1
parenrightbigg
=
Δ
H
vap
R
parenleftbigg
1
T
1

1
T
2
parenrightbigg
ln
parenleftbigg
P
parenrightbigg
parenleftbigg
1
parenrightbigg
ln
P
2
=
32
,
000
8
.
31
01910.0pointsA portion of two volatile liquids are pouredinto an evacuated container, filling the container halfway. The container is then sealed.After equilibrium is established, the measuredpressure is less than expected (negative deviation from Raoult’s Law). What is definitelyTRUE about the mixture?
Explanation:
Raoult’s Law applies to the vapor pressure
of the mixture, so a positive deviation means
that the vapor pressure is higher than ex
pected for an ideal solution and a negative
deviation a lower vapor pressure.
Negative
deviation will occur when the interactions
between the different molecules are some
what stronger than the interactions between
molecules of the same kind.
020
10.0points
Two aqueous solutions are separated by a
semipermeable membrane.
Solution A = 0.34 M KCl
Solution B = 0.64 M KCl
Which of the following statements is TRUE?
1.
K
+
ions flow from solution B to solution
A.