The mass of a non-volatile solute (Molar mass 40) which should be dissolved in `114g` octance to reduce its vapour pressure to `80%` is `2xg`. Find the value of `x`

Answer

5

Explanation

5
`P_(S)=(80/100)P^(0),w=?,m=40`
`W=114g,M_(C_(s)H_(18))=114`
`(P^(0)-P_(s))/(P_(s))=(wxxM)/(mxxW)`
Or `(P^(@)-(80/100)P^(@))/((80/100)P^(@))=(wxx114)/(40xx114)`
`w=10g`