State the class of compound to which ethene belongs.

State the molecular formula of the next member of the homologous series to which ethene belongs.

Justify why ethene has only a single signal in its ¹H NMR spectrum.

Deduce the chemical shift of this signal. Use section 27 of the data booklet.

Suggest two possible products of the incomplete combustion of ethene that would not be formed by complete combustion.

A white solid was formed when ethene was subjected to high pressure.

Deduce the type of reaction that occurred.

Sketch the mechanism for the reaction of propene with hydrogen bromide using curly arrows.

Explain why the major organic product is 2-bromopropane and not 1-bromopropane.

Explain why the major organic product is 2-bromopropane and not 1-bromopropane.

2-bromopropane can be converted directly to propan-2-ol. Identify the reagent required.

Propan-2-ol can also be formed in one step from a compound containing a carbonyl group.

State the name of this compound and the type of reaction that occurs.

alkene ✔

C₃H₆ ✔

Accept structural formula.

hydrogen atoms/protons in same chemical environment ✔

Accept “all H atoms/protons are equivalent”.
Accept “symmetrical”

4.5 to 6.0 «ppm» ✔

Accept a single value within this range.

carbon monoxide/CO AND carbon/C/soot ✔

«addition» polymerization ✔

curly arrow going from C=C to H of HBr AND curly arrow showing Br leaving ✔

representation of carbocation ✔

curly arrow going from lone pair/negative charge on Br⁻ to C⁺ ✔

Award [2 max] for mechanism producing 1-brompropane.

«2-bromopropane involves» formation of more stable «secondary» carbocation/carbonium ion/intermediate
OR
1-bromopropane involves formation of less stable «primary» carbocation/carbonium ion/intermediate ✔

«increased» positive inductive/electron-releasing effect of extra–R group/–CH₃/methyl «increases stability of secondary carbocation» ✔

Award [1] for “more stable due to positive inductive effect”.

Do not award marks for quoting Markovnikov’s rule without any explanation. 

«2-bromopropane involves» formation of more stable «secondary» carbocation/carbonium ion/intermediate
OR
1-bromopropane involves formation of less stable «primary» carbocation/carbonium ion/intermediate ✔

«increased» positive inductive/electron-releasing effect of extra–R group/–CH₃/methyl «increases stability of secondary carbocation» ✔

Award [1] for “more stable due to positive inductive effect”.
Do not award marks for quoting Markovnikov’s rule without any explanation.

sodium hydroxide/NaOH/potassium hydroxide/KOH ✔

Accept «aqueous» hydroxide ions/OH⁻

Name of carbonyl compound:
propanone ✔

Type of reaction:
reduction ✔

Accept other valid alternatives, such as “2-propyl ethanoate” for M1 and “hydrolysis” for M2.