Physical Chemistry MCQ with Answers

Physical Chemistry MCQ with Answers

116) If latent heat of fusion of ice is 80 cal⁄gm at 0^oC, calculate molal depression constant for water:

Answer is:

1.863

Explanation:

K_f = RT_f² ⁄ 1000l_v

117) Calculate the molal elevation constant of water that evaporates at 100^oC with the absorption of 536 cal⁄gm: (R = 2 cal)

Answer is:

0.519^oC

Explanation:

K_b = RT_b² ⁄ 1000l_v

118) 15 gm of methyl alcohol is dissolved in 35 gm of water. What is the mass percentage of methyl alcohol in solution?

Answer is:

0.3

Explanation:

Mass percentage = (mass of methyl alcohol ⁄ mass of solution) x 100

119) Osmotic pressure of a sugar solution at 24^oC is 2.5 atm. Determine the concentration of the solution in gm mol⁄L:

Answer is:

0.1025 mol⁄L

Explanation:

C = π⁄ST

120) 20 gm of a substance was dissolved in 500 mL of water and the osmotic pressure of the solution was found to be 600 mm of Hg at 15^oC. Determine the molecular weight of the substance:

Answer is:

1198

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