CAIE A-Level Chemistry AS 13 An Introduction to As Level Organic Chemistry Questions

Practise organic nomenclature, functional-group recognition, structural formulae, isomerism and reaction representation.

Covered syllabus points

AS organic chemistry conventions and functional group reference 13.1 Formulas, functional groups and nomenclature 13.2 Characteristic organic reactions 13.3 Shapes of organic molecules; σ and π bonds 13.4 Structural isomerism and stereoisomerism

[Maximum number: 1]

Naphtha is a mixture which contains only hydrocarbon molecules.

What is meant by the term hydrocarbon?

[Maximum number: 3]

Fig. 4.1 shows how propane, $\mathrm{C}_{3} \mathrm{H}_{8}$ , can be converted to propanoic acid, $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}$ .

Fig. 4.1

(a)

Reaction 1 in Fig. 4.1 takes place in the presence of sunlight.

\mathrm{C}_{3} \mathrm{H}_{8}+\mathrm{Cl}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}+\mathrm{HCl}

The reaction takes place via initiation, propagation and termination steps.

[ 3 ]

(i)

Reaction 1 is initiated by the bond fission of $\mathrm{Cl}_{2}$ .

State the type of bond fission shown in the initiation step.

[ 1 ]

(ii)

The molecular formula of Q is $\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{Cl}_{2}$ .

Identify the types of structural isomerism and stereoisomerism that a molecule with molecular formula $\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{Cl}_{2}$ can show.
type of structural isomerism
type of stereoisomerism

[ 2 ]

[Maximum number: 3]

Organic compounds can be distinguished using chemical tests and analytical techniques.

(a)

Table 3.1 shows four pairs of organic compounds.

Table 3.1

[ 3 ]

(i)

A1 and A2 are structural isomers.

Define structural isomers.

[ 1 ]

(ii)

Give the systematic name of B2.

[ 1 ]

(iii)

Deduce the molecular formula of D1.

[ 1 ]

molecular formula

$\mathrm{C}_{5} \mathrm{H}_{10} \mathrm{O}$

[Maximum number: 4]

Compound V is a liquid.
V contains 77.2 % carbon, 11.4 % hydrogen and 11.4 % oxygen by mass.
V has a relative molecular mass of 280 .

(a)

W, X and Y have the same molecular formula, $\mathrm{C}_{5} \mathrm{H}_{10} \mathrm{O}$ .

W, X and Y are added separately to different reagents. Observations for these reactions are described in Table 4.1.

Table 4.1

[ 4 ]

(i)

W, X and Y each contain a common functional group.

Name the functional group that is present in all three compounds.

[ 1 ]

(ii)

W could be one of four structural isomers.
- Draw the skeletal formulae for two possible structural isomers of W.
- Describe the type of structural isomerism shown.
isomer 1
isomer 2
type of structural isomerism

[ 3 ]