Question detail

Which of the following best explains why hydrocarbon fuels release energy when they burn?

Try the question, check the answer, then read the explanation to understand the curriculum point.

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At a glance

MCQ

Type

practice

Style

Topic

Carbon compounds as fuels and feedstock

Question

A. The fuel molecules absorb heat from the surroundings.
B. The fuel molecules undergo a reduction reaction.
C. The fuel molecules are oxidised, forming products with lower energy.
D. The fuel molecules are converted into higher energy products.

Answer

The correct option is The fuel molecules are oxidised, forming products with lower energy..

Explanation

The correct option is The fuel molecules are oxidised, forming products with lower energy.. The fuel molecules are oxidised, forming products with lower energy. is correct because it directly supports the approved learning objective to explain that carbon and hydrogen in hydrocarbon fuels are oxidised during combustion. This belongs to Properties and combustion of hydrocarbons within Carbon compounds as fuels and feedstock, so the answer must use the correct organic chemistry context. The other options are incorrect when they confuse the organic family, formula type, reaction condition, product, or property being tested. Keep molecular formula, structural formula, displayed formula, and general formula distinct. Do not confuse alkanes with alkenes, saturated with unsaturated, cracking with combustion, polymers with monomers, or hydrocarbons with oxygen-containing alcohols and carboxylic acids. When formulae are used, preserve the stored notation exactly and explain the GCSE chemistry idea in words rather than using unsupported displayed-formula diagrams.

Common mistake

Oxidation Confusion

Students often confuse oxidation with combustion, thinking that combustion is just burning without understanding that oxidation specifically refers to the reaction of carbon and hydrogen in hydrocarbons with oxygen.

Clarify that oxidation is a chemical process where carbon and hydrogen in hydrocarbons react with oxygen during combustion, leading to the formation of carbon dioxide and water.

Related flashcards

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During the combustion of a hydrocarbon fuel, which of the following statements best describes the change that occurs to the carbon and hydrogen atoms in the fuel molecules?