14.1. Alkanes
A subsection of Chemistry, 9701, through 14. Hydrocarbons
Listing 10 of 122 questions
Crude oil contains a mixture of hydrocarbons together with other organic compounds which may contain nitrogen, oxygen or sulfur in their molecules. At an oil refinery, after the fractional distillation of crude oil, a number of other processes may be used including ‘cracking’, ‘isomerisation’, and ‘reforming’. What is meant by the term ‘cracking ’ and why is it carried out? Outline briefly how the cracking of hydrocarbons would be carried out. Construct a balanced equation for the formation of heptane, C7H16, by cracking tetradecane, C14H30. One of the sulfur-containing compounds present in crude oil is ethanethiol, C2H5SH, the sulfur-containing equivalent of ethanol. Ethanethiol is toxic and is regarded as one of the smelliest compounds in existence. The boiling point of ethanol, C2H5OH, is higher than that of C2H5SH. Suggest a reason for this difference. When ethanethiol is burned in an excess of air, three oxides of different elements are formed. Construct a balanced equation for this reaction. Two of the oxides formed cause serious environmental damage. For each of these oxides, identify the type of pollution caused and describe one consequence of this pollution. A small amount of ethanethiol is added to liquefied gases such as butane that are widely used in portable cooking stoves. Suggest a reason for this. Sulfur-containing compounds are removed from oil products at the refinery. The sulfur is recovered and converted into SO2, which is then used in the Contact process. State the main operating details of the formation of SO3 in the Contact process.
9701_s11_qp_21
THEORY
2011
Paper 2, Variant 1
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Questions Discovered
122