4.173 g of an organic compound (non-electrolyte)lowered the freezing point of 100.0 g nitrobenzene by 2.6 °C. If the K_f of nitrobenzene is 8.1 °C, the molecular mass of the non-electrolyte is ________.

Question

Quizplus · Accepted Answer

The molecular mass can be calculated using the formula ΔTf = (Kf * m), where m is the molality. First, calculate the molality: m = ΔTf / Kf = 2.6 / 8.1 = 0.321 mol/kg. Then, use the formula: molality = moles of solute / kg of solvent. Moles of solute = molality * kg of solvent = 0.321 * 0.1 = 0.0321 moles. Finally, molecular mass = mass of solute / moles of solute = 4.173 g / 0.0321 moles = 130 g/mol.

4173 G of an Organic Compound (Non-Electrolyte)lowered the Freezing Point