assignment
SOLUTION
Question1
- Calculate the mass percentage of benzene (C6 H 6) and
carbon tetrachloride (CCl 4) if 22 g of benzene is dissolved in 122
g of carbon tetrachloride.
Question
2 - Calculate the mole fraction of benzene in solution containing 30% by mass
in carbon tetrachloride.
Question3
- Calculate the molarity of each of the following solutions:
(a)
30 g of Co(NO 3) 2. 6H2 O in 4.3 L of solution
(b)
30 mL of 0.5 M H 2SO4 diluted to 500 mL.
Question
4 - Calculate the mass of urea (NH2 CONH 2) required in
making 2.5 kg of 0.25 molal aqueous solution.
Question5
- Calculate
(a)
molality
(b)
molarity and
(c)
mole fraction of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL –
1.
Question
6 - H 2S, a toxic gas with rotten egg like smell, is used for the
qualitative analysis. If the solubility of H2 S in water at STP is
0.195 m, calculate Henry’s law constant.
Question
7 - Henry’s law constant for CO2 in water is 1.67x108 Pa
at 298 K. Calculate the quantity of CO2 in 500 mL of soda water when
packed under 2.5 atm CO 2 pressure at 298 K
Question
8- The vapour pressure of pure liquids A and B are 450 and 700 mm Hg
respectively, at 350 K . Find out the composition of the liquid mixture if
total vapour pressure is 600 mm Hg. Also find the composition of the vapour
phase.
Question
9 -Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50 g of urea (NH2
CONH2 ) is dissolved in 850 g of water. Calculate the vapour
pressure of water for this solution and its relative lowering.
Question
10 -Boiling point of water at 750 mm Hg is 99.63°C. How much sucrose is to be
added to 500 g of water such that it boils at 100°C
Question
11 - Calculate the mass of ascorbic acid (Vitamin C, C6 H8 O
6) to be dissolved in 75 g of acetic acid to lower its melting point by
1.5°C. K f = 3.9 K kg
mol-1.
Question
12 Calculate the osmotic pressure in pascals exerted by a solution prepared by
dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL of water at 37°C.