Chemistry 0620 · IGCSE · Alkenes

Alkenes — practice question

Alkenes and carboxylic acids each belong to families of compounds that are alike in their chemical behaviour, but their reactions are not the same.
(a)[1]

State the term used for a ‘family’ of compounds that are similar.

(b)[1]

State the general formula for alkenes.

(c(i))[1]

But-2-ene undergoes an addition reaction with aqueous bromine. Describe the colour change that is seen when but-2-ene is added to aqueous bromine from ____________ to ____________.

(c(ii))[1]

State the meaning of the term addition reaction.

(c(iii))[2]

Write the chemical equation for the reaction of but-2-ene with bromine.

(c(iv))[1]

But-2-ene forms a polymer. Suggest the name of the polymer produced from but-2-ene.

(c(v))[2]

Name and draw one structural isomer of but-2-ene. Include all atoms and all bonds in the drawing.

(d(i))[1]

Deduce the empirical formula for butanoic acid.

(d(ii))[2]

Complete the chemical equation for the reaction of butanoic acid with sodium carbonate, Na$_2$CO$_3$. $2\text{CH}_3\text{CH}_2\text{CH}_2\text{COOH} + \text{Na}_2\text{CO}_3 \rightarrow$ ____________ + ____________ + ____________

(d(iii))[2]

Name the organic compound formed, then draw its structure. Include all atoms and all bonds in the drawing.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: the homologous series

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