10 g of aluminum was dipped into a solution of copper chloride, while the mass

10 g of aluminum was dipped into a solution of copper chloride, while the mass of aluminum increased by up to 16.9 g. What amount of aluminum reacted.

Given:
m1 (plates) = 10 g
m2 (plates) = 16.9 g

Find:
m react. (Al) -?

1) 3CuCl2 + 2Al => 2AlCl3 + 3Cu ↓;
2) Let n react. (Al) = (x) mol;
3) m react. (Al) = n * M = x * 27 = (27x) g;
4) n (Cu) = n reag. (Al) * 3/2 = x * 3/2 = (1.5x) mol;
5) m (Cu) = n * M = 1.5x * 64 = (96x) g;
6) m2 (plates) – m1 (plates) = m (Cu) – m react. (Al);
16.9 – 10 = 96x – 27x;
x = 0.1;
7) m react. (Al) = x * 27 = 0.1 * 27 = 2.7 g.

Answer: The mass of aluminum that has reacted is 2.7 g.