how much sucrose is to be added to 500 g of water such that it boils at 100°C

Solution of NCERT In Text Questions-2.10

Question - 2.10 - Boiling point of water at 750 mm Hg is 99.63°C. How much sucrose is to be added to 500 g of water such that it boils at 100°C.

Solution:

Given,

Elevation of boiling point

Mass of water (W_A) = 500 g

Molar mass (M_B) of sucrose (C₁₂H₂₂O₁₁) = 12 x 12 + 1 x 22 + 16 x 11 = 342 g mol ^{– 1}

Molal constant for water (K_b) = 0.52 K kg mol ^{– 1}

Therefore, W_B = ?

We know that,

Thus, 121.67 g of sucrose to be added.