The correct relation between elevation of boiling point and mass of solute is

Options

A. `m_(2)=(K_(b)*w_(2))/(DeltaT_(b)*w_(1))`
B. `m_(2)=(K_(b)*w_(1))/(DeltaT_(b)*w_(2))`
C. `M_(2)=( Delta T_(b)*K_(b))/(w_(1)*w_(2))`
D. `M_(2)=(Delta_(b)*w_(1))/(K_(b)*w_(2))`

Answer

A

Explanation

For dilute solutions, the elevation in boiling point is directly proportional to the molal concentration of the solute in solution (m)
Thus `DeltaT_(b)propm`
`DeltaT_(b)=k_(b)m`
Where, `k_(b)` is molal boiling point elevation constant. As molality (m) `=("Moles of solute"(n_(2)))/("Mass of solvent"(W_(1))"(in kg)")`
Moles of solute `(n_(2))=(W_(2))/(M_(2))`
`:." "Delta T _(b)=(k_(b)xxW_(2))/(M_(2)xxW_(1))`
`rArr" "M_(2)=(K_(b)*W_(2))/(DeltaT_(b)*W_(1))`