Final answer:
A larger mass of Sucrose than Aluminum sulfate would be needed to reduce the vapor pressure of water by the same amount, due to Sucrose not ionizing while Aluminum sulfate does.
Step-by-step explanation:
The question asks which solute would require a larger mass to reduce the vapor pressure of 500 grams of water by the same amount at the same temperature. According to Raoult's law, the reduction in vapor pressure depends on the number of solute particles rather than the type of particles. Since Aluminum sulfate (Al2(SO4)3) ionizes into more particles than Sucrose (C12H22O11), which does not ionize, you would need a larger mass of Sucrose to achieve the same decrease in vapor pressure as a smaller mass of Aluminum sulfate.