hydrate (chemistry) question?

4 ⤊

hydrate (chemistry) question?

the formula for hydrate is CuSO4 (times) 5H2O, how do i calculate mass percent of water in this? also i can use atomic masses from the periodic table. please help me!

2007-10-18 10:37:26 · 2 answers · asked by cindsterr 3 in Science & Mathematics ➔ Chemistry

2 answers

Atomic weights: Cu=63.5 S=32 O=16 H=1 H2O=18 CuSO4=159.5 CuSO4*5H2O=250 5H2O=90

90gH2O/250gCuSO4*5H2O x 100% = 36%

2007-10-18 10:47:49 · answer #1 · answered by steve_geo1 7 · 1⤊ 0⤋

the mass percent of water is the mass of water in the pentahydrate divided by the mass of the entire pentahydrate salt multiplied by 100

water = 18 g/mol so 5 H2O = 90 g/mol

CuSO4.5H2O has a mass of 249.5 g/mol

so mass percent = (90/249.5) x 100 = 36 %

2007-10-18 17:42:46 · answer #2 · answered by Anonymous · 3⤊ 0⤋