Question

Aluminum bronze contains 92.0% copper and 8.0% aluminum. What maximum mass of aluminum bronze can be prepared from 73.5g of copper and 42.2g of aluminum? Initially I tried dividing 73.5g by 0.92, and I thought I have found the max mass of aluminum bronze. But then I tried using 70.0g of copper which gave me a result of about 82.17g of total mass of aluminum bronze. How should I calculate it accurately so that I can maximize the use of both metals?

Answer 1

The ratio of aluminum bronze components is:

92.0 Cu / 8.0 Al

The ratio of Cu and Al avilable is: 73.5 Cu / 42.2 Al

Then, it is evident that Al is in excess and Cu is the limitant material.

So, you need two work with the open proportion 92.0/ 8.0 = 73.5Cu / x

=> x = 73.5 * 8 / 92 = 6.39

Then, you can use 6.4 grams of Al and 73.5 grams of Cu to prepare 6.39g + 73.5g =  79.89.grams of Bronze.

I hope this helps.