# "Describe" questions — OCR GCSE Chemistry A: Gateway Science (J248)

> 15 questions · chemistry

## How to answer

Say WHAT happens, in order. No reasoning. Structure: 1. First X. 2. Then Y. 3. Then Z. Assessment Objective: AO1. Every "describe" answer on this spec is marked against exactly this pattern.

## Sample questions

1. [Describe how steam cracking is used to produce smaller, more useful molecules from crude oil fractions, and explain why …](https://www.gradenine.co.uk/q/describe-how-steam-cracking-is-used-25703852)
2. [Describe how scientists' understanding of atomic structure changed from Dalton's model to Rutherford's nuclear model, in…](https://www.gradenine.co.uk/q/describe-how-scientists-understanding-of-atomic-27a9deae)
3. [A student is trying to identify the gases produced during an experiment. Describe the tests a student would carry out to…](https://www.gradenine.co.uk/q/a-student-is-trying-to-identify-33760b2f)
4. [Describe how carbon dioxide emissions from human activity contribute to climate change, and explain one consequence of t…](https://www.gradenine.co.uk/q/describe-how-carbon-dioxide-emissions-from-3917fa43)
5. [Describe how increasing the surface area of a solid reactant affects the rate of reaction. Use ideas about particles in …](https://www.gradenine.co.uk/q/describe-how-increasing-the-surface-area-5554be69)
6. [A water treatment plant produces drinking water from river water. The river water contains sand particles and dissolved …](https://www.gradenine.co.uk/q/a-water-treatment-plant-produces-drinking-8025289d)
7. [Describe how crude oil forms and explain why it is described as a finite resource.](https://www.gradenine.co.uk/q/describe-how-crude-oil-forms-and-8cbd18f5)
8. [A student carries out electrolysis of brine (concentrated sodium chloride solution) using inert electrodes. Describe wha…](https://www.gradenine.co.uk/q/a-student-carries-out-electrolysis-of-8fafe1c1)

## Related

- [OCR GCSE Chemistry A: Gateway Science (J248) revision notes](https://www.gradenine.co.uk/learn/ocr-gcse-chemistry-a-gateway-science-j248)
- [OCR GCSE Chemistry A: Gateway Science (J248) past papers](https://www.gradenine.co.uk/past-papers/ocr-gcse-chemistry-a-gateway-science-j248)
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