Question

What is the formula of aluminum carbonate?

Answer 1

`Al_2CO_3)_3`

Explanation:

Aluminium generally has a charge of +3
The electron configuration of Aluminium is `1s^2 2s^2 2p^6 3s^2 3p^1`
=
The 3p electron and the 2 3s electrons are outer valance electrons and are lost to form the +3 charge.

The Carbonate ion has a charge of -2

`1 C =1 xx +4`
`3 O = 3 xx -2 = -6`

`+4 + -6 = -2`

Chemical compounds have a net charge of zero

`2 xx (+3) + 3 xx ( -2) = 0`
`+ 6 + -6 = 0`

so the formula is

`Al_2 (CO_3)_3`

Answer 2

`Al_2` `(CO_3)_3`

Explanation:

Aluminium - `Al^3`
Carbonate - `CO_3^-2`

Because the charge of aluminium is 3 and the charge of carbonate is -2, you need to multiply each to balance out at 6. So, "swap and drop":

2`Al^3` & 3`CO_3^-2`

`Al_2` `(CO_3)_3`