A solution of sucrose (molar mass =342) is prepared by dissolving 688.4 g in 1000 g of water. Calculate
The vapour pressure of solution at 293 K.

Options

A. `0.0229`
B. `0.4`
C. `0.5989`
D. `0.326`

Answer

A

Explanation

Vapour pressure of solution can be calculated from the relation
`(P_(A)^(@)-P_(A))/P_(A)=chi_(B)=(W_(B)//Mw_(B))/(W_(A)//Mw_(A))` Here`W_(A)=1000 g`, `W_(A)=68.4 g`, `P_(A)^(@)=0.023 atm`,`Mw_(A)=18`,`Mw_(B)=342`.
Substituting the values, we get
`(0.023-P_(A))/0.023 =(68.4//342)/(1000//18)`
or
`(0.023-P_(A))/0.023 = 0.0036`
or `0.023 - 0.00008=0.02292` atm.
Vapour pressure of solution = `0.02292` atm.