A student is preparing to do an experiment to determine the mass percent of copper in brass. Unfortunately, while collecting the materials for the experiment, the student learns that there is no nitric acid. The student rationalizes that if should be possible to substitute hydrochloric acid for the nitric acid since they are both strong acids. So the student sets up the experiment using hydrochloric acid. After completing the experiment, the student obtains results that are:  

Answer:

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