Nomenclature and formulaeAQA A-Level Chemistry: Subtopic test

1. 1
   Petrol contains a mixture of alkanes. A chemist analyses one branched alkane with the structural formula CH₃CH(CH₃)CH₂CH₂CH₃ and compares it with the straight-chain alkane that has the same number of carbon atoms.

   (a)

   What is the IUPAC name of the branched alkane?

   [1 mark]

   • A4-methylpentane
   • B1,1-dimethylbutane
   • C3-methylpentane
   • D2-methylpentane

   (b)

   What is the empirical formula of the straight-chain alkane?

   [1 mark]

   • AC₆H₁₄
   • BC₃H₇
   • CCH₂
   • DC₆H₁₂

   (c)

   State what is meant by a homologous series.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A solvent supplier labels its bottles with systematic names. The stock list includes an alcohol with the structural formula CH₃CH(OH)CH₂CH₃, a dihalogenoalkane with the structural formula CH₃CHBrCH₂Cl, and a halogenoalkane with the structural formula (CH₃)₃CCl.

   (a)

   What is the IUPAC name of the alcohol with the structural formula CH₃CH(OH)CH₂CH₃?

   [1 mark]

   • AButan-2-ol
   • BButan-1-ol
   • C2-methylpropan-2-ol
   • D1-methylpropan-1-ol

   (b)

   What is the IUPAC name of CH₃CHBrCH₂Cl?

   [1 mark]

   • A1-bromo-2-chloropropane
   • B2-chloro-1-bromopropane
   • C2-bromo-1-chloropropane
   • D1-chloro-2-bromopropane

   (c)

   Write the structural formula of 2-chloro-2-methylpropane and give its molecular formula.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A stock room holds three hydrocarbons. Compound P has the structural formula CH₃CH=CHCH₂CH₃. Compound Q has the structural formula CH₂=C(CH₃)CH₂CH₃. Compound R is a ring of five carbon atoms joined by single bonds, in which one carbon atom carries a methyl group.

   (a)

   Give the IUPAC names of P, Q and R.

   [3 marks]

   (b)

   Give the molecular formulae of P, Q and R, and the general formula that applies to all three compounds.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A teacher is preparing a data sheet of compounds that contain six carbon atoms. Each entry must give the correct IUPAC name and molecular formula.

   (a)

   Hexane has structural isomers of molecular formula C₆H₁₄ with these structural formulae: CH₃(CH₂)₄CH₃, CH₃CH(CH₃)CH₂CH₂CH₃, CH₃CH₂CH(CH₃)CH₂CH₃, CH₃CH(CH₃)CH(CH₃)CH₃ and CH₃C(CH₃)₂CH₂CH₃. Name each isomer and explain why they are structural isomers.

   [6 marks]

   (b)

   Explain, step by step, how the IUPAC name of the alcohol CH₃CH(CH₃)CH(OH)CH₂CH₃ is deduced, and give its molecular formula.

   [6 marks]

   Total for question 4: 12 marks

End of questions