Question: how many milliliters of boiling water are required to dissolve 25 g of phthalic acid?
Answer: From the data you have provided you would need 138.8mL of hot water to dissolve 25g of phthalic acid. If this was then cooled down there would be 0.75g of phthalic acid left in solution, leaving you with 24.25g of phthalic acid.