How do you balance Co(s)+Cl2(g)?
I keep getting this incorrect: 2Co(s)+3Cl2(g)-> 2CoCl3

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.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

the dissolution of polymer can be thermodynamically described in 2 steps.