Assignment

1. A solution of 0.450 g of urea (molar mass = 60 g·mol⁻¹) in 22.5 g of water showed a boiling point elevation of 0.170 °C. Urea has van ’t Hoff factor i = 1. Calculate the molal elevation constant (K_b) of water.
2. 0.15 g of a substance dissolved in 15 g of solvent boiled at a temperature higher by 0.216 °C than the pure solvent. Calculate the molecular weight of the substance. (Molal elevation constant for the solvent K_b = 2.16 K·kg·mol⁻¹.)
3. Determine the molecular weight of a non-volatile solute (glucose) by ebullioscopy using water as the solvent. Given: K_b = 0.512 °C·kg·mol⁻¹, i = 1, W_A = 10.2 g (solute), W_B = 2 g (solvent).
4. Determine the boiling point elevation constant K_b of the solvent chloroform using sulfur as the solute. Given: W_A = 5 g (solute), W_B = 2 g (solvent), molar mass of sulfur M_B = 256.52 g·mol⁻¹.
5. Determine the apparent molecular weight of an electrolyte (Bezamide) in carbon tetrachloride. Given: K_b = 4.88 °C·kg·mol⁻¹, i = 1, W_A = 5 g (solute), W_B = 2 g (solvent).