Here we have to get the amount of zinc oxide will react with 5 moles of carbon to produce Zn metal and carbon di-oxide.
5 moles of carbon will react with 813.8 g of ZnO.
The reaction between zinc oxide (ZnO) and carbon (C) can be shown as-
2ZnO + C = 2Zn + CO₂↑
Thus we can see that 2 moles of ZnO reacts with 1 mole of Carbon. So 5 moles carbon will react with 5×2 = 10 moles of ZnO.
Now the molecular weight of ZnO is 81.38 g/mol. Thus 10 moles of ZnO is equivalent to 10×81.38 = 813.8 gm.
Thus 5 moles of carbon will react with 813.8 g of ZnO.