MOHX has  KSP  4 × 10-12 and solubility 10-4M. The value of x is

MOHx⇌M+x+xOH-                      s        xs ksp =sxsx 4×10-12=10-4x10-4x xx ×10-4x=4×10-8  ;  22×10-4×2=4×10-8By putting x=2 the equation is satisfied. Hence x = 2