Question

copper (||) sulphate pentahydrate crystals experiment

Give possible sources of error that may have caused a discrepancy in your percent yield (try to be as specific as possible) - Dura form of heat.

Answer 1

Percentage yield= $\frac{\text{Actual amount of desired product}\times 100}{\text{theoretical yield}}$

Errors

1.The chance of forming supersaturated solution of copper sulfate which means that copper sulfate stays more in solution rather than separating as solid crystal which will lead to crystal yield.Then we have to use a little amount of solid copper sulfate as 'seed' to encourage crystal growth.This little seed can contribute its weight to the actual weight amount desired crystals.

2.Crystal loss during filtration

3.The crystals are not dried before before taking the final weight..Obviously wet crystal will have higher weight.

4.Solution lost due to poor handling ,so some amount compound gets lost along with the solution.

5. Copper Sulfate stays as CuSO₄.xH₂O where x range from 0 to 5 ..even though the predominant form is CuSO₄.5H₂O, other forms can introduce discrepancy during initial weight calculation before the experiment and final weight calculation of the crystals after the experiment.