Jawabanmu

2014-06-12T14:46:39+07:00
CaSO4 ⇒ Ca2+ + SO42-
  s              s           s
Ksp = s²
2,8 x 10^-4 = s²
s = 1,67 x 10^-2

M = (gr/Mr)(1000/V)
1,67 x 10^-2 = (gr/136)(1/2,5)
gr = 567,8 x 10^-2 = 5,678 gram