Chemistry

A student performed a practical in the laboratory to calculate the enthalpy change for the displacement reaction between zinc metal and copper(II) sulphate solution. Their experimental value was ΔH = -192 kJmol-1. They worked out that the total apparatus error was 5.2%. The data book value for the enthalpy change was ΔH = -217 kJmol-1.

Is the student’s result accurate? Explain your answer.

My answer was it isn't because despite the apparatus error, it is only 202. What else would I include in my answer. Errors during the experiment?

Is this A-level?
I GCSE

it depends on the marks of the question. if its a 1 marker, then all you will have to write is whether it is or isn't and what the correct value is, with the total apparatus error. However, if its more than 1/2 marks, you will have to write how they can improve on the accuracy. So, for example in a reaction of heating different alcohols, one of the ways to improve accuracy is by putting a thermal layer on the apparatus. Another way is by enforcing the standard conditions, such as standard temperature.