A factory makes polymers from alkenes. A cylinder of hydrocarbon gas is labelled as an alkene, but it may contain an alkane instead.
Before using it, a chemist bubbles a sample of the gas through bromine water. The bromine water stays orange.
Which conclusion about the gas is correct?
The gas is an alkene, as labelled.
The gas has reacted with the bromine water.
The gas is an alkane, not an alkene.
The gas is a mixture of an alkane and an alkene.
91 exam-style questions on AQA GCSE Chemistry 7.1 Carbon compounds as fuels and feedstock, covering 7.1.1 Crude oil, hydrocarbons and alkanes, 7.1.2 Fractional distillation and petrochemicals, 7.1.3 Properties of hydrocarbons, and 7.1.4 Cracking and alkenes. Each one has a worked solution and a mark scheme showing where the marks go.