Respostas

2013-09-27T17:22:29-03:00
Massa Molar Al2S3 = 2*27 + 3*32 = 150g/mol

1 mol --------- 150g
x mols --------200g

150x = 200

x = 200/150 = 20/15 mols

Proporção Al ----- Al2S3 = 2 para 1

Al2S3 = 20/15 mols

Al = 2 * 20/15 = 40/15 mols

Massa Molar Al = 27g/mol

27g -------- 1 mol
x g --------40/15 mols

x = 27 * 40 / 15

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x = 72 gramas de Alumínio
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1 5 1