Organic chemistry: Practice Questions

Which of the following compounds is a member of the alkane homologous series and exists as a gas at room temperature and pressure (r.t.p.)?

Ethene reacts with steam in an addition reaction to form ethanol. What are the essential conditions required for this industrial process?

Which statement correctly describes a characteristic of the homologous series of alkanes?

The diagram represents a section of a polymer chain produced from a specific alkene monomer. Which monomer was used to produce this polymer?

The equation for the complete combustion of ethanol is shown below:
\( C_2H_5OH + xO_2 \to yCO_2 + zH_2O \)
What are the values of the stoichiometric coefficients \( x \), \( y \), and \( z \)?

Ethanol is industrially produced by the reaction of ethene with steam. State the name of the catalyst used and describe the temperature and pressure conditions required for this addition reaction.

Nylon is a synthetic polyamide formed through condensation polymerisation. Deduce the structural representation of the repeating linkage in nylon and explain how its formation differs from the addition polymerisation used to create poly(ethene), with reference to the by-products involved.

In the industrial production of nylon, identify the two different functional groups that must be present on the monomers to form the amide linkage and describe why this process is categorized as a condensation reaction rather than an addition reaction.

Hydrocarbons are obtained from petroleum and are used as fuels and as starting materials for many chemical products.

a) State the meaning of the term hydrocarbon.

b) Alkanes are a homologous series of saturated hydrocarbons. State the meaning of the term saturated in this context.

c) Long-chain alkanes can be broken down into smaller, more useful molecules using heat and a catalyst. Name this process and state one reason why it is important for the chemical industry.

The structure of an ethene molecule is shown in the diagram.

a) Ethene, \(C_2H_4\), undergoes addition polymerisation to form poly(ethene). Draw the structural formula of a portion of poly(ethene) showing two repeating units. Include the continuation bonds at each end of the structure.

b) Nylon is a synthetic polymer formed by condensation polymerisation. State two differences between the formation of a condensation polymer like nylon and the formation of an addition polymer like poly(ethene).

c) In an experiment, ethene gas is bubbled through a test tube containing aqueous bromine. Describe the colour change observed in the test tube and explain why this reaction does not occur with ethane.