18 g of a non-volatile solute A is dissolved in 1 kg of water, the boiling point of water is raised to 373.51 K. Given Kb for water is 0.52 K kg mol-1, Boiling point of water is 373.15 K at 1.013 bar pressure. The molecular weight of the solid A is
Answer & explanation
Correct answer: option 2
Elevation in boiling point, ΔTb = 373.51 - 373.15 = 0.36 K
ΔTb = kb m
0.36 = 0.52 x \(\frac{\frac{18}{x}}{1}\)
x = \(\frac{18 × 0.52}{0.36}\)
x = 26 g mol-1