Problems
1. Calculate the vapor pressure of a mixture containing
252 g of n-pentane (Mw = 72) and 1400 g of n-eptane (Mw = 100) at
20oC. The vapor pressure of n-pentane and n-eptane are 420
mm Hg and 36 mm Hg respectively.
Solution
2. Calculate the boiling point (at 1 atm) of a solution containing
116 g of acetone (Mw = 58) and 72 g of water (Mw = 18) by using the following
table:
Temperature
oC
|
Vapor pressure (atm)
Acetone
|
Vapor pressure (atm)
Water
|
|
60
|
1.14
|
0.198
|
|
70
|
1.58
|
0.312
|
|
80
|
2.12
|
0.456
|
|
90
|
2.81
|
0.694
|
3. A mixture of water and acetone at 756 mm boils at 70oC.
Calculate the percentage composition of the mixture using the following
table:
Temperature
oC
|
Vapor pressure (atm)
Acetone
|
Vapor pressure (atm)
Water
|
|
60
|
1.14
|
0.198
|
|
70
|
1.58
|
0.312
|
|
80
|
2.12
|
0.456
|
|
90
|
2.81
|
0.694
|
4. The addition of 114 grams of sucrose to 1000 grams of water
lowers the vapor pressure of water from 17.540 to 17.448. Calculate the
molecular weight of sucrose.
5. Calculate the osmotic pressure ofa suspension containing 60g/l
of solid particles each particle having a mass of 10-9 grams
(1 nanogram)
6. Calculate the osmotic pressure of a solution 0.1 molale of
sucrose (Mw = 342) at 20oC.
|