Question

A solution containing 12.5 g of non-electrolyte substance in 185 g of water shows boiling point elevation of 0.80 K. Calculate the molar mass of the substance. (`K_b=0.52 K kg mol^(-1)`)
A. `"53.06 g mol"^(-1)`
B. `"25.3 g mol"^(-1)`
C. `"16.08 g mol"^(-1)`
D. `"43.92 g mol"^(-1)`

Answer 1

Correct Answer - D
`M_B=(K_bxxW_B)/(DeltaT_bxxW_A)=(0.52xx12.5)/(0.80 xx 0.185)=43.92 g mol^(-1) (because 185 g =0.185 kg ) `