12. (16 pts) A piece of solid aluminum is added to 300.0ml of 0.250MCuCl2(aq). The unbalanced reaction is: CuCl2(aq)+Al(s)Cu(s)+AlCl3(aq) A. (12 pts) How many grams must the piece of aluminum (Al) weigh in order to cause all the copper (Cu) to precipitate out of solution? 1.35g B. (4 pts) After the reaction is run, the copper metal is recovered then dried and weighed. The actual mass of copper metal produced is found to be 3.2g. What is the percent yield? 67.1%