Solutions Class 12th question paper

Solutions Test 20 Questions 20 Marks Time 1 Hour

1: Calculate molality of 2.5 g of ethanoic acid (CH3COOH) in 75 g of benzene.   

2: If N2 gas is bubbled through water at 293 K, how many millimoles of N2 gas would dissolve in 1 litre of water? Assume that N2 exerts a partial pressure of 0.987 bar. Given that Henry’s law constant for N2 at 293 K is 76.48 kbar.

3: Vapour pressure of chloroform (CHCl3) and dichloromethane (CH2Cl2) at 298 K are P₁⁰ 200 mm Hg and P₂⁰ 415 mm Hg respectively. (i) Calculate the vapour pressure of the solution prepared by mixing 25.5 g of CHCl3 and 40 g of CH2Cl2 at 298 K and, (ii) mole fractions of each component in vapour phase.

4: The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non-electrolyte solid weighing 0.5 g when added to 39.0 g of benzene (molar mass 78 g mol^-1). Vapour pressure of the solution, then, is 0.845 bar. What is the molar mass of the solid substance?

5: 18 g of glucose, C6H12O6, is dissolved in 1 kg of water in a saucepan.At what temperature will water boil at 1.013 bar? Kb for water is 0.52 K kg mol^-1.

6: The boiling point of benzene is 353.23 K. When 1.80 g(w₂) of a non-volatile solute was dissolved in 90 g(w₁) of benzene, the boiling point is raised to 354.11 K. Calculate the molar mass (M₂₎ of the solute. Kb for benzene is 2.53 K kg mol^–1

7: 45 g of ethylene glycol (C H O ) is mixed with 600 g of water. Calculate(a) the freezing point depression and (b) the freezing point of the solution.

8: 1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol^–1. Find the molar mass of the solute?

9: 200 cm³ (v)of an aqueous solution of a protein contains 1.26 g(w₂) of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10^-3 bar. Calculate the molar mass of the protein?

10: At  36 g of glucose present in a litre of its solution has an osmotic pressure of  If the osmotic pressure of the solution is  at the same temperature, what would be its concentration?

11: Definition of solutions and give example of types of solutions?

12: Write the definition of molarity, molality and PPM?

13: Give definition of henry’s law and its formula and application and effect of temperature in dissolution of gas?

14: Give roaults law and its formula? Give the formula for composition of vapour phase?

15:Define Ideal solution ? give 3 examples of it?

16: What is positive and negative deviation of roaults law explain with 2-2 example each?also draw graph?

17:What is minimum boiling and maximum boiling Azeotropes? Give example?

18: what id colligative properties? Explain with example?

19: What is osmosis and osmotic pressure? Explain Reverse Osmosis and Water Purification?

20: What is Vont Hoffs Factor ? Give all the 3 formulas