Answer :
Final answer:
To calculate the mass of urea needed to achieve a specific vapor pressure in a solution with water, Raoult's Law and additional data on vapor pressure are required, which are not provided in the question.
Explanation:
The question involves calculating the mass of urea, CO(NH₂)₂, needed to be dissolved in 225 g of water at 35 degrees Celsius to produce a solution with a specific vapor pressure. To solve this problem, we need to apply Raoult's Law, which relates the vapor pressure of the solution to the mole fraction of the solvent. Unfortunately, the question does not provide the necessary data such as the vapor pressure of pure water at 35 degrees Celsius or the specific vapor pressure reduction due to the solute. Typically, for nonvolatile solutes like urea, the vapor pressure of the solution decreases as more solute is added. The exact mass of urea needed to achieve the desired vapor pressure would depend on its impact on the solvent's activity and the colligative properties of the solution. Without additional data to calculate the mole fraction or molality of the solution, a precise numerical answer cannot be provided.