Calculate the vapor pressure over the solution, the amount of vapor pressure is lowered at 25°c and 100°c?
To calculate the vapor pressure over a solution, you need the mole fraction of the solute and the vapor pressure of the pure solvent at the given temperature.
1. Determine the mole fraction of the solute: The mole fraction of the solute (Xsolute) is calculated by dividing the moles of the solute (nSolute) by the total moles in the solution (nTotal):
Xsolute = nSolute / nTotal
2. Find the vapor pressure of the pure solvent: You need to know the vapor pressure of the pure solvent (Psolvent) at both 25°C and 100°C. This information is typically given or can be obtained from reference sources.
3. Calculate the vapor pressure over the solution:
Psolution = Xsolute * Psolvent
Using this information, you can now calculate the vapor pressure over the solution at both 25°C and 100°C. Just make sure to substitute the appropriate values for Xsolute and Psolvent into the equation.
Note: The amount of vapor pressure lowered by the solute is determined by comparing the vapor pressure of the pure solvent with the vapor pressure over the solution. The difference in vapor pressure gives you an indication of how much the presence of the solute decreased the vapor pressure.