Final answer:
The mass percent of the caffeine solution is approximately 5.48% when 4.35 g of caffeine is dissolved in 75 g of benzene.
Step-by-step explanation:
The mass percent of a caffeine solution made by dissolving 4.35 g of caffeine in 75 g of benzene is calculated by the formula: Mass percent = (mass of solute / (mass of solute + mass of solvent)) × 100%. Here, the mass of the solute (caffeine) is 4.35 g and the mass of the solvent (benzene) is 75 g. Substituting the given values into the formula gives:
Mass percent = (4.35 g / (4.35 g + 75 g)) × 100% = (4.35 g / 79.35 g) × 100% ≈ 5.48%
Therefore, the mass percent of caffeine in the solution is approximately 5.48%.