Answer to Question #133305 in Chemistry for marie

Question

Ignition of MgNH4PO4·6H2O produces NH3, H2O and magnesium pyrophosphate, Mg2P2O7. Complete the balance equation for this reaction. If 5.00 g of MgNH4PO4·6H2O are ignited, how many grams of Mg2P2O7 would be formed?

Answer 1

2MgNH₄PO₄·6H₂O + O₂ = 2NH₃ + 7H₂O + Mg₂P₂O₇

M (MgNH₄PO₄·6H₂O) = 245 g/mol

M (Mg₂P₂O₇) = 126.6 g/mol

n (MgNH₄PO₄·6H₂O) = m/M = 5/254=0.02 mol

n (Mg₂P₂O₇) = 1/2 x n (MgNH₄PO₄·6H₂O) = 0.02/2 = 0.01 mol

m (Mg₂P₂O₇) = n x M = 0.01 x 126.6 = 1.3 g