Answer:
10
Explanation:
The balanced equation shows that you produce one Al molecule using 3Na molecules. If you increase the amount of Na to 30 molecules, you are taking the original amount of Na and multiplying by 10. The equation would have to be re-balanced as shown below. Therefore you'd multiply the amount of Al on the right side by 10 also.
30Na + 10AlCl3 => 30NaCl + 10Al