Question

balance the chemical equation using the smallest possible whole number coefficients. if the coefficient is 1, you may leave it blank. al (s) + cucl₂ (aq) → alcl₃ (aq) + cu (s)

Explanation:

Step1: Balance Cl atoms

Find the least - common multiple of 2 and 3 (the sub - scripts of Cl in \(CuCl_2\) and \(AlCl_3\)). The LCM of 2 and 3 is 6. So, we give \(CuCl_2\) a coefficient of 3 (\(3\times2 = 6\) Cl atoms) and \(AlCl_3\) a coefficient of 2 (\(2\times3=6\) Cl atoms).
The equation becomes \(Al+3CuCl_2
ightarrow2AlCl_3 + Cu\)

Step2: Balance Al and Cu atoms

Now, for Al atoms: on the right - hand side, we have 2 \(Al\) atoms from \(2AlCl_3\). So, we give \(Al\) on the left - hand side a coefficient of 2.
For Cu atoms: on the left - hand side, we have 3 \(Cu\) atoms from \(3CuCl_2\). So, we give \(Cu\) on the right - hand side a coefficient of 3.

Answer:

\(2Al + 3CuCl_2
ightarrow2AlCl_3+3Cu\)