# Butane (C₄H₁₀) is a hydrocarbon used in camping gas. A student says that when butane burns completely in oxygen, the total mass of the products must equal the total mass of the reactants. Explain why the student is correct, and describe what products are formed during complete combustion of butane.

> Eduqas A-Level Chemistry — 3.2 Hydrocarbons · Explain · 5 marks

> Butane (C₄H₁₀) is a hydrocarbon used as a fuel in camping gas canisters. When ignited, butane reacts with oxygen in the air.

## Mark scheme (5 marks)

1. The student is correct because of the law of conservation of mass
2. No atoms are lost or made during a chemical reaction
3. The atoms are simply rearranged to form new substances / the same atoms appear on both sides of the equation
4. Carbon dioxide (CO₂) is produced during complete combustion
5. Water (H₂O) is produced during complete combustion

## Key terms

- [complete combustion](https://www.gradenine.co.uk/glossary/complete-combustion)
- [hydrocarbon](https://www.gradenine.co.uk/glossary/hydrocarbon)

## Related

- [Revision notes for Eduqas A-Level Chemistry](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/butane-c-h-is-a-hydrocarbon-used-7c078bc7) · Published by Druglandscape Ltd.