ABCD is a rectangle angle A= 16x+6y and angle B = 2x+12y

The answer to your question is 3 moles of AlCl₃

Explanation:

Process

1.- Write and balance the equation

                  Al(NO₃)₃ + 3NaCl   ⇒   3NaNO₃  +  AlCl₃

2.- Determine the limiting reactant

Theoretical proportion     1 mol Al(NO₃)₃ :  3 moles of NaCl                  

Experimental proportion   4 moles Al(NO₃)₃ : 9 moles NaCl

From these values, we determine that the limiting reactant is NaCl because the number of moles increases three times and the number of moles of Al(NO₃)₃  increases four times.

3.- Determine the amount of AlCl₃ using proportions

                       3 moles of NaCl 1 mol of AlCl₃

                       9 moles of NaCl  x

                       x = (9 x 1) / 3

                       x = 9 /3

                       x = 3 moles