Chemical Changes
This term, all year 10 classes will be studying a new unit in GCSE Chemistry called Chemical Changes. As part of this, their lab skills are put to the test by trying to make blue copper sulphate crystals.
This is a GCSE required practical, so remembering and understanding the various stages is essential knowledge.
Choosing the Acid and Base: Students needed to select a suitable acid and base combination to produce copper sulphate. The only suitable acid was hydrochloric acid but we discussed the pros and cons of using various bases, settling on copper oxide (a black powder).
Making the salt: Whilst making the salt was a simple process of adding the copper oxide to warm acid, the key point was understanding why it needed to be added in excess (which is to ensure all of the acid has reacted and doesn’t contaminate the product).
Separation: Once the salt solution had been made, the excess copper oxide needed to be filtered out, leaving a bright blue copper sulphate solution.
Evaporation and crystallisation: The aim was making dry salt crystals, so the solution was then heated to remove some of the water before allowing the remaining liquid to slowly evaporate and the crystals to form.
Participating in this practical and others like it, offers numerous educational benefits:
Application of Knowledge: Students applied their theoretical understanding of chemical reactions to real-world scenarios, reinforcing key concepts learned in class.
Personal responsibility: Working in a busy classroom, in groups, with potentially dangerous chemicals and various pieces of glassware, required students to show maturity and responsibility.
Critical Thinking: Students were encouraged to think critically and problem-solve throughout the experiment, especially when troubleshooting unexpected outcomes.
Enthusiasm for Science: Science is a practical subject and, although I like to think all Chemistry lessons at PGHS are interesting, putting scientific knowledge to use in a practical way helps build engagement with and enthusiasm for the subject.
Supporting Your Child’s Learning: A great way of consolidating understanding and retaining knowledge is to explain what you have learned to someone else. This is particularly the case with a required practical. Asking your daughter what she’s doing in her science lessons is a great way of helping her to recap this essential knowledge.
Mr Coogan
Science Department
