Question

The molal lowering of vapour pressure for water at $100^{o}C$ , is

• A. 760 mm
• B. 750 mm
• C. 13.43 mm
• D. 0.760 mm

Answer 1

Answer: (C)

$\frac{P^0-P_S}{P^0}=\frac{n_2}{n_1+n_2}$

$P^0-P_S=\left[\frac{1}{1+\frac{1000}{18}}\right]\times 760=13.43mm$