Ответ:

дано

m(ppa H3PO4) = 32.7 g

W(H3PO4) = 12%

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m(Mg) = ?

m(H3PO4)= 32.7 * 12 % / 100% = 3.924 g

3Mg+2H3PO4-->Mg3(PO4)2+3H2

M(H3PO4) = 98 g/mol

n(H3PO4) = m/M = 3.924 / 98 = 0.04mol

3n(Mg) = 2n (H3PO4)

n(Mg) = 3*0.4 / 2 = 0.6 mol

M(Mg) =24 g/mol

m(Mg) = n*M = 0.6 * 24 = 14.4 g

ответ 14.4 г

Объяснение: