Which is the correct mole ratio for aluminum chloride to chlorine in the chemical reaction alcl3 br2? albr3 cl2?

To answer this item what needs to be done is to write the correct and balanced chemical reaction as below.

2AlCl3 + 3Br2 - - > 2AlBr3 + 3Cl2

From the chemical reaction above, we can say that every 2 moles of AlCl3 will produce 3 moles of Cl2. Thus, the answer is 2:3.