Question

Gold can be recovered from sea water by reacting the water with zinc, which is refined from zinc oxide. The zinc displaces the gold in the water. What mass of gold can be recovered if 2.00g of ZnO and an excess of sea water are available?
2ZnO + C -> 2Zn + CO2
2Au^+3 + 3Zn -> 3Zn^+2 + 2Au

Answer 1

6ZnO+ 3C + 4Au+3 >> 6Zn+2 + 4Au + 3CO2

so for each mole of ZnO consumed, one gets 4/6 mole of Gold


massgold=2gZnO*1moleZnO/molmassAuO * 2 moleAu/3moleZnO * molmassAu/1moleAu

Answer 2

Could you break that down a little? I don't completely understand.

Answer 3

You're just working another stoichiometry problem.
2 g ZnO = how many moles.
moles = grams/molar mass.

??moles ZnO x (4 moles Au/6 moles ZnO = xx moles Au.

Convert moles Au to grams.