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 K_b 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

26.0 g mol^-1

Elevation in boiling point, ΔT_b = 373.51 - 373.15 = 0.36 K

ΔT_b = k_b m

0.36 = 0.52 x \(\frac{\frac{18}{x}}{1}\)

x = \(\frac{18 × 0.52}{0.36}\) 

x = 26 g mol^-1