Answer:
Step-by-step explanation:
Cobalt either has two or 4 as it's valance number == usually 2
Co + Cl2 ==) CoCl2 and that balances it.
I was quite surprised to find out that that Cl3+ actually does exist, but I'm pretty sure only in a grade level about yours. It sort of looks like this
Co3+ + 1e- ===> Co2+
If there was a Co3+ ion, your equation would be correct the way it is done. That's why I went to check it.