ANSWER
The coefficient of Cl2 in the reaction is 1
EXPLANATION
Firstly, we need to balance the given equation of the reaction
[tex]\text{ Fe}_{(s)}\text{ + Cl}_{2(g)}\text{ }\rightarrow\text{ FeCl}_2[/tex]In the above reaction, 1 mole Fe reacts with 1 mole Cl2 to give 1 mole FeCl2
Therefore, the coefficient of Cl2 in the reaction is 1