Formula of bicarbonate of a metal is M(HCO3)3. The formula of its pyrophosphate is
Formula of bicarbonate of Metal is M(HCO3)3. As we know the valency of bicarbonate is 1. So by criss-cross method valency of M is 3. Formula of pyrophosphate is P2O73-. Valency of pyrophosphate is 3. Both M and pyrophosphate have valency 3. Thus the formula of Metal pyrophosphate is M3(P2O7)3 or MP2O7.