Calculate the mass percent of water in the hydrate Al2(SO4)3·18H2O to four sig. figs.

Question

I got this answer 60.23, but I just am confused on how to correctly write the units

Answer 1

I don't know how you obtained that answer but the unit is %. The molar mass of Al2(SO4)3.18H2O is 666.429 and 18 mols H2O = 324.275
so %H2O = about (324/666)*100 = ?%.

You can do it more accurately.

Answer 2

48.65