The alkenes are a homologous series of hydrocarbons.

1. (a)Give the general formula for the alkenes.[1]
2. (b)(i)The structure of an alkene is shown. ΗΗΗΗ H-C-C-C=C-H HH Name this alkene.[1]
3. (b)(ii)Explain how this structure shows that alkenes are: unsaturated hydrocarbons.[2]
4. (c)Alkenes are produced by cracking some fractions obtained from the fractional distillation of petroleum (crude oil). State the meaning of the term cracking.[2]
5. (d)Carbon monoxide is formed when alkenes undergo incomplete combustion. State one effect of carbon monoxide on health.[1]
6. (e)(i)Alkenes react with bromine to form compounds containing carbon, hydrogen and bromine. A compound contains 22.2% carbon, 3.70% hydrogen and 74.1% bromine by mass. Calculate the empirical formula of this compound. empirical formula[2]
7. (e)(ii)A different compound of carbon, hydrogen and bromine has the empirical formula C3H2Br. The relative molecular mass of this compound is 236. Deduce the molecular formula of this compound. molecular formula[1]

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