Question

Here's one last equation I can't balance:

Al{subscript 2}(SO{subscript 4}){subscript 3} + ZnCl{subscript 2} -> AlCl{subscript 3} + ZnSO{subscript 4}
Please help, and thanks again.

Responses
Al2(SO4)3 + 3ZnCl2 ---> 2AlCl3 + ?___ZnSO4

What is your thinking? What goes in the blank?

I would guess that a 3 goes there. Am I correct?

Answer 1

Yes, a 3 goes there but why are you guessing? There are 3 Zn on the left so you need 3 Zn on the right. There are 3 SO4 [from Al2(SO4)3] on the left so you need 3 SO4 on the right. Placing a 3 in front of ZnSO4 does the job of providing 3 Zn and 3 sulfate ions on the right.