M.15 (b)

[Brigitte Phung 1F]

The problem: Aluminum metal reacts with chlorine gas to produce aluminum chloride. In one preparation, 255g of aluminum is placed in a container holding 535 g of chlorine gas. After reaction ceases, it is found that 300g of aluminum chloride has been produced. (a) Write the balanced equation for the reaction. (b) What mass of aluminum chloride can be produced by these reactants? (c) What is the percentage yield of aluminum chloride?

In the solutions manual, the grams of each reactant are converted directly into the theoretical yield of AlCl3 without first determining the limiting reactant. In problems worded like part (b), should all of the work for both of the reactants be shown or would it be sufficient to just find the limiting reactant and find the theoretical yield from there?

[Jessica Yang 1J]

I think it would be sufficient enough to just find the limiting reactant and then follow by finding the theoretical yield. I think the book just went an extra step.

[Julia Meno 1D]

You could do it either way! The solutions manual chose to calculate the grams of AlCl3 produced from both reactants, and then determined the limiting reactant as the one which produced the least amount of AlCl3. But you could also calculate the moles of Cl2 and Al respectively, determine the limiting reactant based on their molar ratios, and then use the moles of the limiting reactant to find the theoretical yield. Both work the same, it's just about preference of methods!