(a)i. State two characteristics of a homologous series. (ii) Explain briefly why there are differences...

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 electroplate a copper ornament with silver.