Respuesta :

Answer:

0.05 mol

Explanation:

Moles = Mass / Mr (Relative formula mass)

Ar of aluminium = 27

Ar of sulphur = 32

Ar of oxygen = 16

Mr of Al2(S2O3)2 = (27×2)+((32×2)×3)+((16×3)×3)= 390

Moles = 18.5g / 390

Moles = 0.05 mol