Chemistry 5070 · O Level · Alkenes

Alkenes — practice question

Alkenes form a homologous series of hydrocarbons.
(a)[1]

Give the general formula of the alkenes.

(b(i))[1]

Name the alkene shown.

(b(ii))[2]

Explain how this structure demonstrates that alkenes are: unsaturated hydrocarbons

(c)[2]

Alkenes are made when some fractions from the fractional distillation of petroleum (crude oil) are cracked. State the meaning of the term cracking.

(d)[1]

Carbon monoxide is produced when alkenes undergo incomplete combustion. State one effect of carbon monoxide on health.

(e(i))[2]

A compound is made up of 22.2% carbon, 3.70% hydrogen and 74.1% bromine by mass. Calculate the empirical formula of this compound.

(e(ii))[1]

A separate compound containing carbon, hydrogen and bromine has empirical formula $\text{C}_3\text{H}_2\text{Br}$. The relative molecular mass of this compound is 236. Deduce the molecular formula of this compound.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: CₙH₂ₙ

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI