Final answer:
The student's error in adding half as much 1,10-phenanthroline as she was supposed to will result in reduced actual and theoretical yields, while the percent yield remains unaffected.
Step-by-step explanation:
The student's error in adding half as much 1,10-phenanthroline as she was supposed to will affect the actual, theoretical, and percent yields of the red crystal synthesis.
The theoretical yield is the amount of product that can be produced based on the balanced chemical equation, and it is calculated by stoichiometry. Since the student added only half of the required amount, the theoretical yield will be halved as well.
The actual yield is the amount of product obtained in the experiment, and it is often less than the theoretical yield due to various reasons such as side reactions or incomplete recovery. In this case, the actual yield will also be reduced to half of what it would have been.
The percent yield is the ratio of the actual yield to the theoretical yield, multiplied by 100%. Since both the actual and theoretical yields are halved, the percent yield will still be the same as if the correct amount of 1,10-phenanthroline was added.