Respostas

2013-12-01T14:32:42-02:00
N = m/M 

Dados: 
m = 56g 
M[Al(SO₄)₃] =  1 X A(Al) + 3 x A (S) + 12 x A (O) = 26,98 + 3* 32,07 + 12 * 16,00 = 315,19 g.mol⁻¹

n = 56/315,19 <=> n = 0,178 mol 
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