Hallar la masa molecular de :H₂SO₄ =NH₃ =Fe₂O₃ =Mg(OH)₂ =CaCO₃ =Na₂SO₄ =CaSO₄ 2H ₂O =?

H₂SO₄

Ar(H) = 1

Ar(S) = 32

Ar(O) = 16

H = 1 * 2 = 2

S = 12 * 1 = 12

O = 16 * 4 = 64

Masa molecular : 2 + 12 + 64 = 78 g / mol

NH₃

Ar(N) = 14

Ar(H) = 1

N = 14 * 1 = 14

H = 1 * 3 = 3

Masa molecular : 14 + 3 = 17 g / mol

Fe₂O₃

Ar(Fe) = 56

Ar(O) = 16

Fe = 56 * 2 = 112

O = 16 * 3 = 48

Masa molecular : 112 + 48 = 160 g / mol

Mg(OH)₂

Ar(Mg) = 24

Ar(O) = 16

Ar(H) = 1

Mg = 24 * 1 = 24

O = 16 * 2 = 32

H = 1 * 2 = 2

Masa molecular : 24 + 32 + 2 = 58 g / mol

CaCO₃

Ar(Ca) = 40

Ar(C) = 12

Ar(O) = 16

Ca = 2 * 1 = 40

C = 12 * 1 = 12

O = 16 * 3 = 48

Masa molecular : 40 + 12 + 48 = 100 g / mol

Na₂SO₄

Ar(Na) = 23

Ar(S) = 32

Ar(O) = 16

Na = 23 * 2 = 46

S = 32 * 1 = 32

O = 16 * 4 = 64

Masa molecular : 46 + 32 + 64 = 142 g / mol

CaSO₄ 2H ₂O

Ar(Ca) = 40

Ar(S) = 32

Ar(O) = 16

Ar(H) = 1

Ca = 40 * 1 = 40

S = 32 * 1 = 32

O = 16 * 4 = 64

H = 1 * 4 = 4

O = 16 * 2 = 32

Masa molecular : 40 + 32 + 64 + 4 + 32 = 176 g / mol.