To determine how many chlorine atoms are on the products side of the given reaction \( 2Al + 6HCl → 2AlCl_3 + 3H_2 \), we need to look at the product \( 2AlCl_3 \).
Each \( AlCl_3 \) molecule contains 3 chlorine (Cl) atoms. Since there are 2 moles of \( AlCl_3 \) in the products:
\[ 2 , \text{moles of } AlCl_3 \times 3 , \text{Cl atoms per } AlCl_3 = 6 , \text{Cl atoms} \]
Thus, there are 6 chlorine atoms on the products side of the reaction.
The correct answer is 6.