Physical Chemistry MCQ with Answers

Physical Chemistry MCQ with Answers

131) A solution obtained by dissolving 0.2 gm of solute in 100 cc of solution in benzene at 21^oC develops at a rise of 2 mm of Hg osmotic equilibrium. Find molarity of the solution: (Density of solution = 0.88 gm⁄cc)

Answer is:

8.3 x 10⁻³ mol⁄L

132) When mercuric iodide is added to the aqueous solution of potassium iodide, the:

Answer is:

Freezing point is raised

Explanation:

There is a decrease in number of ions present in the solution, so ΔT_f decreases.

133) The osmotic pressure of urea solution is 500 mm of Hg at 10^oC. If the solution is diluted and temperature is raised to 25^oC, the osmotic pressure decreases to 105.3 mm of Hg. What is the extent of dilution?

Answer is:

5 times

134) Benzene and toluene form nearly ideal solutions. At 20^oC, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20^oC for a solution containing 78 gm of benzene and 46 gm of toluene in torr is:

Answer is:

50

Explanation:

P_B = P_B^o x χ_B

135) Two solutions of a substance are mixed in the following manner: 480 mL of 1.5M of solution 1 + 520 mL of 1.2M of solution 2. What is the molarity of the final mixture?

Answer is:

1.344M

Explanation:

M₁V₁ + M₂V₂ = M₃V₃

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