Give one reason for filtering the mixture in Step 5.
How to approach this question
Step 5 is filtration. Think about what is in the beaker at the end of Step 4. There is the liquid product (copper sulfate solution) and the unreacted solid (excess copper carbonate). What is the purpose of filtration in this context?
Full Answer
To remove the excess/unreacted copper carbonate.
Filtration is a separation technique used to separate an insoluble solid from a liquid. In this experiment, excess copper carbonate powder was added to ensure all the acid reacted. This means that after the reaction is complete, there is unreacted solid copper carbonate mixed with the copper sulfate solution. Filtering the mixture allows the copper sulfate solution (the filtrate) to pass through the filter paper, while the solid unreacted copper carbonate (the residue) is trapped.
Common mistakes
✗ Saying "to remove impurities" - this is too vague. Be specific about the substance being removed.
✗ Saying "to get the crystals" - filtration removes the solid, it doesn't produce the crystals.
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