The balanced chemical equation for the reaction between Al2(CO3)3 and ZnCl2 to form ZnCO3 and AlCl3 is:

$$Al_2(CO_3)_3 + 3ZnCl_2 -> 3ZnCO_3 + 2AlCl_3$$

The coefficients in the balanced equation are:

- Al2(CO3)3: 1

- ZnCl2: 3

- ZnCO3: 3

- AlCl3: 2