The table below lists six organic compounds, labeled J to O, and shows their structures or formulas:
| Letter | Compound Name / Structure |
|---|---|
| J | Propane, CH3CH2CH3\text{CH}_3\text{CH}_2\text{CH}_3CH3CH2CH3 |
| K | But-1-ene, CH2=CHCH2CH3\text{CH}_2=\text{CHCH}_2\text{CH}_3CH2=CHCH2CH3 |
| L | Butane, CH3CH2CH2CH3\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3CH3CH2CH2CH3 |
| M | Hex-2-ene, CH3CH=CHCH2CH2CH3\text{CH}_3\text{CH}=\text{CHCH}_2\text{CH}_2\text{CH}_3CH3CH=CHCH2CH2CH3 |
| N | Cyclohexane, a cyclic molecule containing a ring of six CH2\text{CH}_2CH2 groups |
| O | Octane, CH3CH2CH2CH2CH2CH2CH2CH3\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_3CH3CH2CH2CH2CH2CH2CH2CH3 |
Explain why all of these compounds are described as hydrocarbons.
Why are K and M described as unsaturated?
Which letter represents the member of the homologous series of alkanes with three carbon atoms?
Which letters represent compounds that have the empirical formula CH2\text{CH}_2CH2?
Compound N has the same general formula as an alkene. Why does N not decolourise bromine water?
One of the compounds in the table reacts with bromine to form Z, a compound with the percentage composition by mass: C=22.2%\text{C} = 22.2\%C=22.2%, H=3.7%\text{H} = 3.7\%H=3.7%, Br=74.1%\text{Br} = 74.1\%Br=74.1%. (Relative atomic masses: C=12\text{C} = 12C=12, H=1\text{H} = 1H=1, Br=80\text{Br} = 80Br=80)
Show, by calculation, that the empirical formula of Z is C2H4Br\text{C}_2\text{H}_4\text{Br}C2H4Br.
One of the compounds in the table reacts with bromine to form Z, a compound with the percentage composition by mass: C=22.2%\text{C} = 22.2\%C=22.2%, H=3.7%\text{H} = 3.7\%H=3.7%, Br=74.1%\text{Br} = 74.1\%Br=74.1%. (Relative atomic masses: C=12\text{C} = 12C=12, H=1\text{H} = 1H=1, Br=80\text{Br} = 80Br=80)
The relative formula mass of Z is 216. Deduce the molecular formula of Z.
