The vapour pressure of 100 g water reduces from 3000 Nm ⁻² to 2985 Nm ⁻² when 5 g of substance ' X ' is dissolved in it. Substance ' X ' is

Step-by-step solution

aligned p^ -p_s p^ = n n+N & = w m w m + W M w m & W M p^ -p_s p^ & = w / m W / M = w m M W 3000-2985 3000 & = 5 m 18 100 m & = 5 18 3000 15 100 m & =180 aligned 180 is the molecular weight of glucose ( C ₆ H ₁₂ O ₆ ) , thus the substance ' X ' is glucose.