diketahui 1,71 gr(OH)2 tepat bereaksi dengan 100ml HCL 0,2 M sesuai reaksi x(OH)2 + HCL → xCl2 + H2O jika Ar O= 16 , H = 1 ,berapa Ar x ?

mol x(OH)₂ = 1,71/Mr
mol HCl = M x V = 0,2 x 0,1 = 0,02 mol

perb mol = perb koefisien
 x(OH)₂ + 2HCl → xCl₂ + 2H₂O
1,71/Mr    0,02

1,71/Mr = 0,01
Mr  x(OH)₂= 171

x + (16.2) + (1.2) = 171
x + 32 +2 = 171
x + 34 = 171
x = 137

Ar X = 137 gr/mol