The correct relation between the elevation in boiling point and the molar mass of a solute is: ($W_1$ and $W_2$ are respectively weight of solvent & solute)

• Correct answer
  A

  ${\text{M}}_2=\frac{{\text{K}}_{\text{b}}\times {\text{W}}_2\times 1000}{{\text{ΔT}}_{\text{b}}\times {\text{W}}_1}$
• B

  ${\text{M}}_2=\frac{{\text{K}}_{\text{b}}\times {\text{W}}_1\times 1000}{{\text{ΔT}}_{\text{b}}\times {\text{W}}_2}$
• C

  ${\text{M}}_2=\frac{{\text{ΔT}}_{\text{b}}\times {\text{K}}_{\text{b}}\times 1000}{{\text{W}}_1\times {\text{W}}_2}$
• D

  ${\text{M}}_2=\frac{{\text{ΔT}}_{\text{b}}\times {\text{W}}_1\times 1000}{{\text{K}}_{\text{b}}\times {\text{W}}_2}$

Hence, the correct answer is option: 'A'.