# NCERT Solutions Class 12 Chemistry Chapter 2 Solutions in text questions

1. Calculate the mass percentage of benzene (C6H6) and carbon tetrachloride (CCl4) if 22g of benzene is dissolved in 122g of carbon tetrachloride.

2. Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride

3. Calculate the molarity of each of the following solutions (a) 30g of CO(NO3)2.6H2O in 4.3 L of solution (b) 30 mL of 0.5 M H2SO4 diluted to 500ml.

4. Calculate the mass of urea (NH2CONH2) required in making 2.5kg of 0.25 molar aqueous solution.

5. Calculate (a) molality (b) molarity (c) mole fraction of KI if the density of 20% (mass / mass) aqueous KI is 1.202 g/ mL.

6. H2S , a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H2S in water at STP is 0.195 m, calculate henry law constant.

7. Henry law constant for CO2 in water is 1.67 x 108 Pa at 298K. Calculate the quantity of CO2 in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298K.

8. The vapor pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350K. Find out the composition of liquid mixture if total vapor pressure is 600mm Hg . Also, find the composition of vapor phase.

9. Vapor pressure of pure water at 298K is 23.8mm Hg. 50 g of urea (NH2CONH2) is dissolved in 850 g of water. Calculate the vapor pressure of water for this solution and its relative lowering.

Hence, the vapor pressure of water in solution is 23.4 mm of Hg and its relative lowering is 0.0173.

10. Boiling point of water at 750 mm Hg is 99.63°C. How much sucrose is to be added to 500g of water such that it boils at 100°C.

11. Calculate the mass of ascorbic acid (Vitamin,C – C6H8O6) to be dissolved in 75g of acetic acid to lower its melting point by 1.5°C. Kf = 3.9 K Kg/mol.

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.