Calculate the molality of a solution if the boiling point elevation is 1.024 °C.
Practice Questions
Q1
Calculate the molality of a solution if the boiling point elevation is 1.024 °C. (K_b for water = 0.512 °C kg/mol)
1 mol/kg
2 mol/kg
0.5 mol/kg
0.25 mol/kg
Questions & Step-by-Step Solutions
Calculate the molality of a solution if the boiling point elevation is 1.024 °C. (K_b for water = 0.512 °C kg/mol)
Step 1: Understand the formula for molality (m) in relation to boiling point elevation: m = ΔT_b / (i * K_b).
Step 2: Identify the values given in the problem: ΔT_b (boiling point elevation) is 1.024 °C, and K_b (boiling point constant for water) is 0.512 °C kg/mol.
Step 3: Determine the van 't Hoff factor (i). For this example, we will assume the solute is a non-electrolyte that dissociates into 2 particles, so i = 2.
Step 4: Substitute the values into the formula: m = 1.024 / (2 * 0.512).
Step 5: Calculate the denominator: 2 * 0.512 = 1.024.
Step 6: Divide the boiling point elevation by the calculated denominator: 1.024 / 1.024 = 1.
Step 7: Conclude that the molality of the solution is 1 mol/kg.
Boiling Point Elevation – The increase in boiling point of a solvent due to the presence of a solute, which is directly proportional to the molality of the solution.
Molality Calculation – Molality is calculated using the formula: Molality = ΔT_b / (i * K_b), where ΔT_b is the boiling point elevation, i is the van 't Hoff factor, and K_b is the ebullioscopic constant.
