# "Describe and explain" questions — OCR A-Level Chemistry B: Salters (H433)

> 5 questions · chemistry

## How to answer

"describe and explain" questions from OCR A-Level Chemistry B: Salters (H433). Read the rubric carefully — the marking points cluster into scientific ideas rather than free-form prose.

## Sample questions

1. [A student is investigating the composition of the universe and the Earth's crust. The student learns that the most abund…](https://www.gradenine.co.uk/q/a-student-is-investigating-the-composition-26506fe4)
2. [Seawater contains many dissolved substances. A scientist collects seawater samples from two locations: one near a busy s…](https://www.gradenine.co.uk/q/seawater-contains-many-dissolved-substances-a-57f27f3d)
3. [A student wants to separate the dyes in a sample of black ink using chromatography. Describe how the student would carry…](https://www.gradenine.co.uk/q/a-student-wants-to-separate-the-5b1d6e16)
4. [Starch is a naturally occurring polymer found in foods such as potatoes and bread. Describe the structure of starch as a…](https://www.gradenine.co.uk/q/starch-is-a-naturally-occurring-polymer-95e5b57c)
5. [Iodine is an element that can be extracted from seaweed. A student carries out a series of reactions to obtain pure iodi…](https://www.gradenine.co.uk/q/iodine-is-an-element-that-can-aa0c1739)

## Related

- [OCR A-Level Chemistry B: Salters (H433) revision notes](https://www.gradenine.co.uk/learn/ocr-a-level-chemistry-b-salters-h433)
- [OCR A-Level Chemistry B: Salters (H433) past papers](https://www.gradenine.co.uk/past-papers/ocr-a-level-chemistry-b-salters-h433)
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