Calculation of Molality of Solution
1. Given Data:
- Mole fraction of C2H5OH (ethanol) in water solution = 0.050
- Formula of ethanol (C2H5OH)
2. Mole Fraction Formula:
- The mole fraction of a component in a solution is the ratio of the number of moles of that component to the total number of moles of all components in the solution.
3. Calculation:
- Let's assume the total number of moles in the solution is 1 mole.
- Since the mole fraction of ethanol is 0.050, the number of moles of ethanol = 0.050 moles.
- The number of moles of water = 1 - 0.050 = 0.950 moles.
4. Molality Formula:
- Molality (m) is defined as the number of moles of solute per kilogram of solvent. It is given by the formula:
m = (moles of solute) / (mass of solvent in kg)
5. Calculate Molality:
- Since the mass of 1 mole of water is approximately 18 g, the mass of 0.950 moles of water = 0.950 * 18 g = 17.1 g = 0.0171 kg.
- Molality of the solution = (0.050 moles) / (0.0171 kg) ≈ 2.92 mol/kg
Therefore, the molality of the solution of C2H5OH in water, where the mole fraction of C2H5OH is 0.050, is approximately 2.92 mol/kg.