Final answer:
The percent error is calculated using the formula: |(Experimental Value - True Value) / True Value| x 100%. In this case, it is 7.06%. The mistaken answer of 88°C as the percent error is incorrect because percent error should be a percentage, not a temperature value.
Step-by-step explanation:
To calculate the percent error in the measurement of the temperature of a solution, we use the formula:
Percent Error = |(Experimental Value - True Value) / True Value| x 100%
In this case, the student measured 79 degrees Celsius while the true temperature was 85 degrees Celsius. The percent error would be calculated as follows:
|(79 - 85) / 85| x 100% = |(-6) / 85| x 100% = 7.06%
An answer of 88 degrees Celsius as the percent error is incorrect because the percent error should be expressed as a percentage, not a temperature. The mistake might come from misunderstanding the formula, where a temperature difference is applied in the numerator but after completing the calculation, it should be presented as a percentage, not as another temperature reading.