The ______________ yield is the maximum amount of product possible in a reaction. This determines the amount of product that should be produced in a perfect setting

Maybe you want the word "theoretical"

I suspect theoretical is the word that goes there. To leave the blank as a bland to make it read "The yield is the maximum amount ......" actually is not correct. Technically I don't think "The percentage yield is the ...." is correct either. Percentage yield is the yield you get but it is not the maximum amount of product you could get. The after Christmas blahs I guess.

You may want percent in that blank spot but the statement is true without the word percent.

The ______________ yield is the maximum amount of product possible in a reaction. This determines the amount of product that should be produced in a perfect setting.

Good

Theoretical

Yes, "theoretical" is the word that fits in the blank to make the statement complete and accurate.