Answer:
E. 2 : 3
Step-by-step explanation:
Aluminium carbonate is a neutral compound made by aluminium ion, Al³⁺ and carbonate ion, CO₃²⁻. As is neutral, the formula must be:
Al₂(CO₃)₃.
2 Al₃⁺ = 6 positives charges
3 CO₃²⁻ = 6 negative charges
Thus, the simplest whole number ratio between Al³⁺ and CO₃²⁻ must be:
2:3
And right answer is:
E. 2 : 3