Organic chemistry quiz

Duration: 45 minutes
Total marks: 22

Answer all questions. Show structural formulae clearly and include reaction conditions where requested.

Section A: Multiple choice (5 marks)

Q1 (1 mark)

Which is the general formula for alkenes?

A. $C_nH_{2n+2}$
B. $C_nH_{2n}$
C. $C_nH_{2n+1}OH$
D. $C_nH_{2n+1}COOH$

Q2 (1 mark)

Which change occurs from the bottom to the top of a fractional distillation column?

A. Chain length increases.
B. Boiling point increases.
C. Volatility increases.
D. Viscosity increases.

Q3 (1 mark)

What condition is required for methane to react with chlorine by substitution?

A. Ultraviolet light
B. Nickel catalyst
C. Aqueous bromine
D. Steam and an acid catalyst

Q4 (1 mark)

What is observed when an alkene is shaken with aqueous bromine?

A. Colourless solution turns orange-brown.
B. Orange-brown solution becomes colourless.
C. A blue precipitate forms.
D. Effervescence produces hydrogen.

Q5 (1 mark)

Which statement about poly(ethene) is correct?

A. It is made from ethane by condensation polymerisation.
B. It contains –CO–NH– linkages.
C. It forms water at each linkage.
D. It is made from ethene by addition polymerisation.

Section B: Short answer (17 marks)

Q6 (2 marks)

Write the structural formula for each compound:

  1. ethene
  2. ethanol

Q7 (3 marks)

Define a structural isomer. State two characteristics of a homologous series.

Q8 (3 marks)

Explain how fractional distillation separates petroleum. State two changes in fraction properties from the bottom to the top of the column.

Q9 (3 marks)

Propene has structural formula CH2=CHCH3.

  1. Write the repeat unit of poly(propene).
  2. State whether polymerisation is addition or condensation polymerisation.
  3. State whether a small molecule is produced during this polymerisation.

Section C: Extended response (30 marks)

Q10 (6 marks)

Compare methane and ethene.

  1. Write a structural formula for each compound. (2)
  2. State which is saturated and which is unsaturated. (1)
  3. Describe the aqueous bromine test that distinguishes them. (1)
  4. Write a balanced equation for ethene reacting with bromine. (2)

Q11 (6 marks)

Ethanol can be manufactured by fermentation or by catalytic addition of steam.

  1. State the conditions for fermentation. (1)
  2. Write the balanced symbol equation for fermentation of glucose. (1)
  3. Write the equation for ethene reacting with steam to form ethanol. (1)
  4. State the temperature, pressure, and catalyst used for catalytic addition of steam. (1)
  5. State one advantage of fermentation and one advantage of catalytic addition of steam. (2)

Attempt the quiz before checking the mark scheme
Mark Scheme C11 - Organic Chemistry Mark Scheme
Topic Guide: C11 - Organic Chemistry