Which of the following is not a correct chemical equation for a double displacement reaction? (D?)


2HNO3 + Mg(OH)2 yields 2H2O + Mg(NO3)2

H3PO4 + 3NaF yields 3HF + Na3PO4

2KNO2 + BaSO4 yields K2SO4 + Ba(NO2)2

4NaBr + Co(SO3)2 yields Br2SO3 + CoNa4