I) The compound C₆H₁₀ has the general formula CₙH₂ₙ₋₂, which corresponds to an alkyne. With 6 carbon atoms, it is a hexyne.

a)

i) The compound C₆H₁₀ has the general formula CₙH₂ₙ₋₂, which corresponds to an alkyne. With 6 carbon atoms, it is a hexyne.
Name: Hexyne

ii) The compound CH₃CHCH₂ has three carbon atoms and a double bond, making it an alkene.
Name: Propene

b)

i) Step I shows a long chain alkane being converted into ethene (CH₂=CH₂), which is a smaller alkene. This process involves breaking down larger hydrocarbon molecules into smaller, more useful ones.
Name of process: Cracking

ii) To distinguish between ethene (CH₂=CH₂) and ethane (CH₃CH₃), a chemical test for unsaturation can be used.

• Add bromine water (orange/brown) to both compounds.
• Ethene, being an alkene, will undergo an addition reaction with bromine, causing the bromine water to decolorize (turn colorless).

$$\text{CH}_2=\text{CH}_2 + \text{Br}_2 \rightarrow \text{CH}_2\text{Br}-\text{CH}_2\text{Br}$$

• Ethane, being an alkane, will not react with bromine water under normal conditions, and the orange/brown color will persist.