2A1 (s) + 3C12 (g) --> 2AlCl3 (s) (balanced) When 72 grams of aluminum react, the actual yield is 125.5 grams, what is the percent yield?
i got a few mins left

32.3%

Explanation:

Percent yield is defined as:

Actual yield (125.5g) / Theoretical Yield * 100

To find theoretical yield we have to find the moles of aluminium. As 2 moles of Al produce 2 moles of AlCl3, the moles of Al = Moles AlCl3.

With these moles we can find the mass assuming a 100% of yield (Theoretical Yield) as follows:

Moles Al = Moles AlCl3 (Molar mass Al = 26.98g/mol)

72g Al * (1mol / 26.98g) = 2.67 moles AlCl3

Mass AlCl3 (Molar mass: 133.34g/mol)

2.67 moles AlCl3 * (133.34g / mol) = 355.8g AlCl3

Percent Yield = 125.5g / 355.8g * 100 =