How many moles of water are produced if 5.43 mol pbo2 are consumed

this is a stoichiometry based problem

We can solve this by just knowing the balanced chemical equation.The reaction where PbO2 is used and water is produced is

Pb + PbO2 + 2H2SO4 > 2PbSO4 + 2H2O

This is reaction in lead storage battery

so here as per balanced equation one mole of PbO2 is consumed giving two moles of water

so if 5.43 moles of PbO2 we will get = 2 X 5.43 moles of water = 10.86 moles

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.