(a)i. State two characteristics of a homologous series.
(ii) Explain briefly why there are differences in the reaction of ethane and ethene.
(b) When crystals of sodium chloride were warmed with concentrated tetraoxosulphate( VI) acid, a gas was evolved.
(i) Name the gas.
(ii) State two physical properties of the gas.
(iii) Write a balanced chemical equation for the reaction.
(c)i. What are hydrocarbons?
(ii) State two natural sources of hydrocarbons.
(iii) A hydrocarbon contains 83% of carbon by mass. Calculate its empirical formula. [H=1.0, C=12.0]
(d) Draw and label a diagram of a set-up that could be used to electroplate a copper ornament with silver
(ii) Explain briefly why there are differences in the reaction of ethane and ethene.
(b) When crystals of sodium chloride were warmed with concentrated tetraoxosulphate( VI) acid, a gas was evolved.
(i) Name the gas.
(ii) State two physical properties of the gas.
(iii) Write a balanced chemical equation for the reaction.
(c)i. What are hydrocarbons?
(ii) State two natural sources of hydrocarbons.
(iii) A hydrocarbon contains 83% of carbon by mass. Calculate its empirical formula. [H=1.0, C=12.0]
(d) Draw and label a diagram of a set-up that could be used to electroplate a copper ornament with silver
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Correct Answer: Option
Explanation:
(a)i. Characteristics of homologouS series
- All members can be represented by a general formula.
- Each member of the series differs from the next by a constant/fixed number of atoms
- CH\(_{2}\)/ 14 amu
- All members of the series show a gradual change in physical properties such as density.
- AII members have similar chemical properties/same functional groups.
- All members of the group are prepared using a similar chemical method
(ii) Differences in the Reaction of Ethane and Ethene
- Ethane is a saturated hydrocarbon containing a single bond and therefore undergoes mainly substitution reaction while ethene is an unsaturated hydrocarbon containing a double bond and hence undergoes an addition reaction
(b)i. The gas is hydrogen chloride.
(ii) Physical properties of the gas:
- Colourless
- Has choking smell
- Denser than air
- Gas is soluble in water.
- Gas fumes in moist air.
(iii) Write a balanced equation reaction:
2HaCl\(_{(s)}\) + H,SO\(_{4(aq)}\), \(\implies\) Na2SO\(_{4(aq)}\) + 2HC\(_{(g)}\) OR HaCI\(_{(s)}\) + H\(_{2}\)SO\(_{4(aq)}\) \(\implies\) NaHSO\(_{4(aq)}\) + HCl\(_{(g)}\)
(c)i. Hydrocarbons are compounds containing only hydrogen and carbon
(ii) Two Natural Sources of Hydrocarbons:
- Coal
- Petroleum/crude oil Natural gas.
(iii) A hydrocarbon contains 83.0 % of carbon by mass. calculate its emprical formular (H =1.0; C = 12.0).
Solution: C = 83.0 %.
\(\therefore\) % H\(_{2}\) = 100 - 83 17%
(d) Draw and label a diagram of a set-up that could be used to clectroplate a copper ornament with silver.
(a)i. Characteristics of homologouS series
- All members can be represented by a general formula.
- Each member of the series differs from the next by a constant/fixed number of atoms
- CH\(_{2}\)/ 14 amu
- All members of the series show a gradual change in physical properties such as density.
- AII members have similar chemical properties/same functional groups.
- All members of the group are prepared using a similar chemical method
(ii) Differences in the Reaction of Ethane and Ethene
- Ethane is a saturated hydrocarbon containing a single bond and therefore undergoes mainly substitution reaction while ethene is an unsaturated hydrocarbon containing a double bond and hence undergoes an addition reaction
(b)i. The gas is hydrogen chloride.
(ii) Physical properties of the gas:
- Colourless
- Has choking smell
- Denser than air
- Gas is soluble in water.
- Gas fumes in moist air.
(iii) Write a balanced equation reaction:
2HaCl\(_{(s)}\) + H,SO\(_{4(aq)}\), \(\implies\) Na2SO\(_{4(aq)}\) + 2HC\(_{(g)}\) OR HaCI\(_{(s)}\) + H\(_{2}\)SO\(_{4(aq)}\) \(\implies\) NaHSO\(_{4(aq)}\) + HCl\(_{(g)}\)
(c)i. Hydrocarbons are compounds containing only hydrogen and carbon
(ii) Two Natural Sources of Hydrocarbons:
- Coal
- Petroleum/crude oil Natural gas.
(iii) A hydrocarbon contains 83.0 % of carbon by mass. calculate its emprical formular (H =1.0; C = 12.0).
Solution: C = 83.0 %.
\(\therefore\) % H\(_{2}\) = 100 - 83 17%
(d) Draw and label a diagram of a set-up that could be used to clectroplate a copper ornament with silver.