How many moles of water are produced if 5.43 mol pbo2 are consumed?10.9

The correct answer is 10.86 moles.

It is a stoichiometry based problem,  

One can solve this by just knowing the balanced chemical equation. The reaction where PbO2 is used and water is generated is:  

Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O

The mentioned reaction is witnessed in the lead storage battery.  

Therefore, here as per the balanced equation one mole of PbO₂ is consumed providing two moles of water. So, for 5.43 moles of PbO₂, we will get,  

2 × 5.43 moles of water = 10.86 moles.  

the correct answer is 10.9

it's c. elements are placed in rows based on how may valencies electrons have.