Question

Sebanyak 2,8 gram besi direaksikan dngn asam sulfat, persamaan reaksi: Fe(s)+H2SO4(aq) -> Fe2 (SO4)3(aq)+H2(g)
Hitunglah massa besi sulfat yg dihasilkan dan volume gas H2 yang dihasilkan

Answer 1

2 Fe(s) + 3 H2SO4(aq) => Fe2(SO4)3 + 3 H2(g)

massa Fe = 2,8 gr , Ar Fe = 56
mol Fe = 2,8 gr / 56 gr/mol = 0,05 mol
perbandingan koefisien reaksinya = 2 : 3 : 1 : 3
mol Fe2(SO4)3 = 1/2 x mol Fe = 1/2 x 0,05 mol = 0,025 mol
Mr Fe2(SO4)3 = 400
massa Fe2(SO4)3 = 0,025 mol x 400 gr/mol = 10 gram

mol H2 = 3/2 x mol Fe = 3/2 x 0,05 mol = 0,075 mol
V H2 = 0,075 mol x 22,4 liter/mol = 1,68 liter