How many moles of ZnCl_2 will be produced from 23.0 g of Zn, assuming CuCl_2 is available in excess?

Question

Zn+CuCI_2=ZnCI_2+Cu

Answer 1

From the problem and the balanced chemical equation, one mole of zinc will yield one mole of zinc chloride. You started with 23.0 grams of zinc. Dividing this by the atomic mass of zinc (65.38 grams/mole) gives the number of moles

(23.0 grams)/(65.38 grams/mole) = 0.35179 moles of zinc.

The problem assumes that you are given enough copper chloride to completely react all the zinc. The number of grams of zinc is given to three significant figures, so your final answer must also have three significant figures. The final answer is

0.352 moles of zinc chloride can be produced