Question

A single cooper penny was tested three times determine it composition.The first analysis gives a composition 93.2% zinc& 2.8% cooper.The second gave 92.9% zinc & 3.1% cooper & the third gave 93.5% zinc & 3.5% cooper. The actual composition of the penny was 97.6% zinc & 2.4% cooper . were the result precise.

Answer 1

The results from testing the penny's composition were not precise compared to the actual composition, indicating some variability in the measurements.

Step-by-step explanation:

The student has tested a penny three times to determine its composition. The results obtained were not precise, considering that precision refers to the closeness of two or more measurements to each other. In this case, the actual composition of the penny was measured to be 97.6% zinc and 2.4% copper.

The results from the analyses were 93.2% zinc and 2.8% copper, 92.9% zinc and 3.1% copper, and 93.5% zinc and 3.5% copper, respectively, which shows some variation and thus lack of precision. The third result in particular is off by an additional 1.1% in zinc and 1.1% in copper.

Precision in analytical chemistry is crucial as it ensures that if the method were to be repeated, the results would be similar each time.