[tex]n = \frac{masa}{masa \: molec} \\ masa \: \: moleculara \: cuso4 = 64 + 32 + 64 = 160 \\ masa \: molec. = 160 \: g \\ 2 = \frac{masa}{160} = > \\ masa \: = 320 \: g[/tex]
ms =md+mH2O=320 +500=820 g
[tex]c = \frac{320 \times 100}{820} = \frac{32000}{820} = 39.02\%[/tex]