A student used 5.06g of copper sulphate pentahydrate and salicyclic acid in the performance of the experiment. The student recovered 3.094g of salicyclic acid and 2.146g of copper sulphate pentahydrate. What is wrong with the student's result? How might this error have been avoided?

Answer 1

The student's results are incorrect because the sum of the recovered salicylic acid and copper sulphate pentahydrate (3.094g + 2.146g = 5.24g) is greater than the initial mass used in the experiment (5.06g). This suggests that there was some contamination or error during the experiment.

This error could have been avoided by taking the following precautions:

1. Ensuring the weighing balance is properly calibrated and accurate.
2. Using clean and dry containers for weighing and transferring the chemicals.
3. Making sure not to mix any other chemicals or substances which could lead to the observed discrepancy.
4. Recording the measurements carefully and avoiding any errors in calculation.
5. Repeating the experiment to confirm the reproducibility of the results.