Someone please, help me, I need the answers urgent 1) The molecular mass of aluminum sulfate is 342 g/mol. You find through experimentation that the ratio of mass of dry salt to mass of hydrate is a ratio of close to 3/5. What is the percentage water by mass in the hydrate?

2)The molecular mass of anhydrous aluminum sulfate is 342 g/mol. The precise ratio of mass of anhydrous salt to hydrate is 61%. What is the approximate mole ratio of water to salt for aluminum sulfate hydrate? Express your answer as an integer.

3)A 2.914 g sample of gypsum (hydrated calcium sulfate, CaSO4) is heated in a crucible until it reaches a constant mass. The mass of the anhydrous CaSO4 is 2.304 g. How many millimoles of calcium sulfate remain after the heating?