Question

The boiling point of solution containing 68.4 g of sucrose `("molar mass" = 342 g mol^(-1))` in 100 g of water is `(K_(b) "for water" = 0.512 K. kg mol^(-1))`
A. `100.02^(@)C`
B. `98.98^(@)C`
C. `101.02^(@)C`
D. `100.512^(@)C`

Answer 1

Correct Answer - C
`Delta T_(b) = K_(b) xx m = K_(b) xx W_(2)/(M_(2) xx W_(1) (kg))`
`=0.512 xx 68.4/(342 xx 0.1) = 1.024 ^(@) C `
` :. T_(b) = T_(b)^(o) + Delta T_(b) =100 ^(@) C + 1.024^(@)C=101.024^(@)C`