If you’ve just finished the classic single replacement reaction lab —usually with copper(II) chloride and aluminum wire—you’ve probably stared at your beaker and asked: Why is there still aluminum left? and Did I mess up my calculations?
Your measured leftover was . That’s close! Small differences are due to handling, oxidation, or incomplete drying. Percent Yield of Copper (Another Common Question) Theoretical yield of Cu from 0.0372 mol CuCl₂ (1:1 mol ratio CuCl₂ to Cu): [ 0.0372 , \textmol Cu \times 63.55 , \textg/mol = 2.36 , \textg Cu ] leftover aluminum wire lab answer key
[ 2Al + 3CuCl_2 \rightarrow 2AlCl_3 + 3Cu ] If you’ve just finished the classic single replacement