# A student carries out a reaction to produce silver chloride as a precipitate. The theoretical yield of silver chloride is 40.0 g, but the student only collects 28.0 g. Explain why the actual yield is less than the theoretical yield, and describe two practical reasons that could account for this difference in this type of reaction.

> Edexcel GCSE Chemistry (1CH0) — 5.2 Quantitative analysis (Chem only) · Explain · 4 marks

> Silver chloride is an insoluble white solid that can be produced by mixing solutions of silver nitrate and sodium chloride. It is used in photography and specialist glass manufacture.

## Mark scheme (4 marks)

1. The actual yield is less than the theoretical yield because the theoretical yield is the maximum possible mass of product from a reaction / not all reactants are converted to product
2. First practical reason: some precipitate is lost during transfer / filtering / washing of the solid
3. Second practical reason: side reactions / competing reactions produce unwanted by-products, reducing the amount of desired product formed
4. Percentage yield is less than 100% — calculated as (actual yield ÷ theoretical yield) × 100 / the student's percentage yield is 70%

## Key terms

- [actual yield](https://www.gradenine.co.uk/glossary/actual-yield)
- [theoretical yield](https://www.gradenine.co.uk/glossary/theoretical-yield)
- [precipitate](https://www.gradenine.co.uk/glossary/precipitate)

## Related

- [Revision notes for Edexcel GCSE Chemistry (1CH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-carries-out-a-reaction-6690f5c5) · Published by Druglandscape Ltd.