When the following equation is balanced with the lowest whole number coefficients possible, what is the coefficient in front of ZnCl2?
Al (s) + ZnCl2 (aq) --> Zn (s) + AlCl3 (aq)

The options are:
1
2
3
6

I think the correct answer is 1, but I'm not sure.

Respuesta :

It's 3. There are two Cl in the reactants and 3 in the products, and they need to be balanced/equal. Only way to do that is add three on the left side, which will give you 6 Cl (3×2Cl) and then 2 on the other side, which will also give you 6 Cl (2×3Cl)