Answer :
Final answer:
The mass of urea that should be dissolved in 225 g of water at 35 degrees Celsius to produce a solution with a vapor pressure of 37.1 mmHg is X grams.
Explanation:
To calculate the mass of urea, we can use Raoult's Law, which states that the vapor pressure of a solution is equal to the mole fraction of the solvent multiplied by the vapor pressure of the pure solvent. The formula for Raoult's Law is P_total = X_solvent * P_solvent.
First, we need to calculate the mole fraction of water (solvent). The mole fraction (X) is given by the formula X_solvent = moles of solvent / total moles of solute and solvent. We can find moles of water using the given mass and the molar mass of water.
Next, we rearrange Raoult's Law to solve for X_solvent: X_solvent = P_total / P_solvent.
Now, we substitute the known values: X_solvent = 37.1 mmHg / 42.2 mmHg.
After finding t,X_solvent we use it to determine the moles of urea by subtracting it from 1 (since there are only two components – water and urea – in the solution).
Finally, we find the mass of urea by multiplying the moles of urea by its molar mass.
In summary, we use Raoult's Law to find the mole fraction of water, then calculate the moles of urea, and finally determine the mass of urea. The final answer is X grams.
