A-level chemistry subject advisor at the UK exam board OCR. I've previously taught chemistry at secondary schools in Bournemouth and Cambridge. Outside of my employment, I run Compound Interest, a website featuring graphics that look at everyday chemical compounds and concepts.
4 comments by Andy
Minor point on Prof Andrew Parson’s comments about the impact of the A level Chemistry reforms: the first examinations for the new A level specifications didn’t take place until June 2017. This means the changes wouldn’t be a factor in a drop in university student numbers in the 2016-17 year, as students would have still been sitting the legacy A level exam in 2016.
Sorry for the delay getting back to you! I think there are a variety of ways you can prepare students for the more contextual approaches in the new examinations. It's worth bearing in mind that differences in specifications are less pronounced since the reform, so for example OCR Chemistry B examination material can in most cases easily be used in preparation for OCR Chemistry A.
Ways to give students more practice might be to use the pre-release materials used in Chemistry B, in both the new and legacy specifications. These are good for getting students to apply their knowledge to unfamiliar contexts.
Additionally, the RSC's Chemistry Olympiad contains questions which involve the contextual application of knowledge, which might be of use. You can access past papers back to 2003 on Learn Chemistry: bit.ly/olympiadpapers. The questions are certainly more challenging but you could get students to work on them in groups.
I don't know which particular syllabus you're following, but the OCR Chemistry A syllabus states that students should be familiar with "use of a Roman numeral to indicate the magnitude of the oxidation number when an element may have compounds/ions with different oxidation numbers."
The specific examples cited include iron(II) and iron(III). I should probably have also indicated that this isn't limited to transition metals; for example, chlorate(I), chlorate(VII), etc would also fall under this heading.
Hope that makes it clearer!
Thanks, glad you've found it useful!
To give some idea of specific questions where the application of this knowledge was required, in OCR's 2017 examinations there were questions with reaction flowcharts. In these questions, candidates had to fill in either the reagents required to convert between different compounds, or suggest the structures of the resultant compounds where the reagents were provided.
Flowcharts for synthetic routes have also been present in practice papers, again requiring students to either suggest reagents or intermediate product structures with some information provided.