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Consider the following reaction : 3PbCl2 + 2(NH4)3PO4 Pb3(PO4)2 + 6NH4Cl If 72 mmol of PbCl2 is mixed with 50 mmol of (NH4)3PO4, then the amount of Pb3(PO4)2 formed is mmol (nearest integer).
24
Limiting reagent: compare mmol ÷ coefficient
PbCl2: 723 = 24; (NH4)3PO4: 502 = 25
∵ 24 < 25 ⇒ PbCl2 is the limiting reagent
∴ Pb3(PO4)2 formed = 723 = 24 mmol
Answer: 24
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