Question

How do you balance `Zn(OH)_2 + CH_3COOH -> Zn(CH_3COO)_2 + H_2O`?

Answer 1

Use the proton balance method given below to obtain:

`2"CH"_3"COOH" + "Zn"("OH")_2 rarr "Zn"("CH"_3"COO")_2 + 2"H"_2"O"`.

Explanation:

One way to do it is to think of it as a proton donation (acid) reaction and a proton acceptance (base) reaction:

Acid:

`"CH"_3"COOH" rarr "CH"_3"COO"^{-} + "H"^+`

Base:

`"Zn"("OH")_2 + 2 "H"^{+} rarr "Zn"^{2+} + 2 "H"_2"O"`

The acid gives one mole of protons but tge base takes two. To balance the protons take two moles of the acid to one of the base:

`2"CH"_3"COOH" rarr 2"CH"_3"COO"^{-} +2 "H"^+`

`"Zn"("OH")_2 + 2 "H"^{+} rarr "Zn"^{2+} + 2 "H"_2"O"`

Then add them up. The protons cancel and the remaining ions combine to make the salt:

`2"CH"_3"COOH" + "Zn"("OH")_2 rarr "Zn"("CH"_3"COO")_2 + 2"H"_2"O"`