The lowering of vapour pressure due to a solute in a `1 m` aqueous solution at `100^(@)C` is

Options

A. 13.44 mm Hg
B. 14.12 mm Hg
C. 31.2 mm Hg
D. 35.2 mm Hg

Answer

A

Explanation

`m=(x_(B)xx1000)/((1-x_(B))m_(A))x_(B)=` mole fraction of solute
`1=(x_(B)xx1000)/((1-x_(B))xx18)m_(A)=` molar mass of solvent
`x_(B)=0.0176`
`x_(A)=1-0.0176=0.9824`
`p=p_(0)x_(A)`
`= 760xx0.9824=746.62`
`Deltap=p_(0)-p=760-746.62`
`~~13.4`].