Question

A solution containg `12 g` of a non-electrolyte substance in `52 g` of water gave boiling point elevation of `0.40 K` . Calculate the molar mass of the substance. `(K_(b)` for water =` 0.52 K kg mol^(-1))`

Answer 1

The given values are:
`W_(B) = 12 g`,`W_(A) = 52 g`
`DeltaT_(b) = 0.4 K`
Using the formula,
`Mw_(B) = (K_(b) xx W_(B) xx 1000) / (DeltaT_(b) xx W_(A))`
`:. Mw_(B) = (0.52 xx 12xx 1000) /(0.4 xx 52 ) = 300`
Molecular weight of solute is `300 g mol^(-1)`.