Coal gas is made by heating coal in the absence of air.
The list shows the main gases present in coal gas.
carbon dioxide
carbon monoxide
ethene
hydrogen
methane
nitrogen
Which one of these gases is an alkane?
Draw the structure of a molecule of ethene. Show all of the atoms and all of the bonds.
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Petrol is a mixture of hydrocarbons and additives. The combustion of petrol in car engines is a major source of air pollution. This is reduced by catalytic converters.
Petrol is obtained from the gasoline fraction, boiling point range 40 °C to 100 °C, from the distillation of petroleum.
Explain the term fraction.
In many countries, a lead compound of the type Pb(C2H5)n used to be added to petrol to improve its combustion. After combustion, lead oxide was formed.
An analysis of the compound, Pb(C2H5)n, showed that 0.026 moles of Pb was combined with 0.104 moles of C2H5 groups.
What is the value of n? Show how you arrived at your answer.
Some of the pollutants emitted by vehicle exhausts are carbon monoxide, oxides of nitrogen and unburnt hydrocarbons. Explain how the emission of these gases is reduced by a catalytic converter.
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Table 2.1 shows some information about the homologous series of unbranched carboxylic acids.
Table 2.1
|
name |
structure |
boiling point / °C |
|
methanoic acid |
HCOOH |
101 |
|
ethanoic acid |
CH3COOH |
118 |
|
propanoic acid |
CH3CH2COOH |
141 |
|
butanoic acid |
CH3CH2CH2COOH |
164 |
|
pentanoic acid |
CH3CH2CH2CH2COOH |
186 |
One of the characteristics of a homologous series is that it has a general formula.
[1]
[2]
An aqueous solution of propanoic acid is a weak acid.
Define the term acid.
Butanoic acid reacts with ethanol to make an ester.
State the name of the ester made and draw the displayed formula of the ester linkage.
Ethanoic acid is a liquid at room temperature.
Describe the changes in the arrangement and movement of the molecules of ethanoic acid
when it is heated from room temperature to 120°C.
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