Calculation of Mole Fraction of Solvent in 2.5 molal Aqueous Solution
- Definition of Molality:
Molality (m) is defined as the number of moles of solute dissolved in 1 kg of solvent.
- Given Information:
In a 2.5 molal aqueous solution, the molality (m) is 2.5.
- Calculation of Mole Fraction of Solvent:
To calculate the mole fraction of solvent in the solution, we need to consider the mole fraction of solvent (water) and solute (the substance dissolved in water).
- Mole Fraction Formula:
The mole fraction of a component in a solution is given by the formula:
Mole fraction of component = (Number of moles of component) / (Total number of moles in the solution)
- Assuming 1 kg of water:
Since molality is defined as the number of moles of solute dissolved in 1 kg of solvent, we can assume that 1 kg of water is the solvent in this case.
- Calculating Number of Moles of Water:
Since the molality is 2.5 molal, there are 2.5 moles of solute in 1 kg of water.
- Calculating Total Number of Moles in the Solution:
The total number of moles in the solution can be calculated by adding the moles of solute and solvent. In this case, it would be 2.5 moles of solute + 1 mole of solvent (water) = 3.5 moles.
- Calculating Mole Fraction of Solvent:
Using the formula mentioned earlier:
Mole fraction of solvent (water) = 1 / 3.5 = 0.2857
Therefore, the mole fraction of solvent (water) in the 2.5 molal aqueous solution is 0.2857.