(a) Name one product of destructive distillation of coal that is (i) solid (ii) liquid; (iii) gas.
(b) (i) What is the major component of synthetic gas? (ii) Give one reason why synthetic gas is not a major source of air pollution.
(c) (i) Write a balanced chemical equation for the complete combustion of carbon. (ii) State two: I. physical; II. chemical properties of the product in (c)(i).
(d) (i) Name two allotropes of carbon that are I. crystalline, II. amorphous. (ii) State one use of each of the allotropes named in (d)(i).
(e) (i) By means of balanced chemical equations only, outline the process of manufacture of H\(_2\)SO\(_4\), by contact process.
(ii) State the function of H\(_2\)SO\(_4\) in each of the following reaction equations:
I. C\(_2\)H\(_5\)OH\(_{2(l)}\) \(\to\) C\(_2\)H\(_{4(g)}\);
II. Pb(NO\(_{3(g)}\) + H\(_2\)SO\(_{4(g)}\) —> PbSO\(_{4(s)}\) + 2HNO\(_{3(aq)}\)
(a) Products of destructive distillation of coal
- (i) Solid: coke.
- (ii) Liquid: coal tar (also ammoniacal liquor).
- (iii) Gas: coal gas.
(b) Synthetic (producer/water) gas
- (i) Major component: carbon monoxide, CO (together with hydrogen).
- (ii) Reason it is not a major source of air pollution: it burns completely and cleanly to give carbon dioxide and water vapour, producing no soot/smoke and containing no sulphur, so it does not release smoke or sulphur oxides.
(c) Complete combustion of carbon
- (i) \[C + O_2 \to CO_2\]
- (ii) I. Physical properties of CO\(_2\): colourless, odourless gas; denser than air; fairly soluble in water. II. Chemical properties: it is an acidic oxide, turning moist blue litmus red and turning lime water milky; it does not support ordinary combustion (it neither burns nor supports burning).
(d) Allotropes of carbon
- (i) I. Crystalline: diamond and graphite. II. Amorphous: charcoal and coke (also lampblack/soot).
- (ii) Uses: diamond, for cutting/drilling tools (and jewellery); graphite, as a lubricant and as electrodes; charcoal, as a fuel and adsorbent (decolouriser); coke, as a fuel and a reducing agent in the blast furnace.
(e) Contact process and roles of H\(_2\)SO\(_4\)
- (i) \[S + O_2 \to SO_2\] \[2SO_2 + O_2 \rightleftharpoons 2SO_3\] \[SO_3 + H_2SO_4 \to H_2S_2O_7\] \[H_2S_2O_7 + H_2O \to 2H_2SO_4\]
- (ii) I. In \(C_2H_5OH \to C_2H_4 + H_2O\), concentrated H\(_2\)SO\(_4\) acts as a dehydrating agent (it removes water from the ethanol). II. In \(Pb(NO_3)_2 + H_2SO_4 \to PbSO_4 + 2HNO_3\), H\(_2\)SO\(_4\) acts as a non-volatile (less volatile) acid that displaces the more volatile nitric acid from its salt (an acid in double decomposition).
(a) Products of destructive distillation of coal
- (i) Solid: coke.
- (ii) Liquid: coal tar (also ammoniacal liquor).
- (iii) Gas: coal gas.
(b) Synthetic (producer/water) gas
- (i) Major component: carbon monoxide, CO (together with hydrogen).
- (ii) Reason it is not a major source of air pollution: it burns completely and cleanly to give carbon dioxide and water vapour, producing no soot/smoke and containing no sulphur, so it does not release smoke or sulphur oxides.
(c) Complete combustion of carbon
- (i) \[C + O_2 \to CO_2\]
- (ii) I. Physical properties of CO\(_2\): colourless, odourless gas; denser than air; fairly soluble in water. II. Chemical properties: it is an acidic oxide, turning moist blue litmus red and turning lime water milky; it does not support ordinary combustion (it neither burns nor supports burning).
(d) Allotropes of carbon
- (i) I. Crystalline: diamond and graphite. II. Amorphous: charcoal and coke (also lampblack/soot).
- (ii) Uses: diamond, for cutting/drilling tools (and jewellery); graphite, as a lubricant and as electrodes; charcoal, as a fuel and adsorbent (decolouriser); coke, as a fuel and a reducing agent in the blast furnace.
(e) Contact process and roles of H\(_2\)SO\(_4\)
- (i) \[S + O_2 \to SO_2\] \[2SO_2 + O_2 \rightleftharpoons 2SO_3\] \[SO_3 + H_2SO_4 \to H_2S_2O_7\] \[H_2S_2O_7 + H_2O \to 2H_2SO_4\]
- (ii) I. In \(C_2H_5OH \to C_2H_4 + H_2O\), concentrated H\(_2\)SO\(_4\) acts as a dehydrating agent (it removes water from the ethanol). II. In \(Pb(NO_3)_2 + H_2SO_4 \to PbSO_4 + 2HNO_3\), H\(_2\)SO\(_4\) acts as a non-volatile (less volatile) acid that displaces the more volatile nitric acid from its salt (an acid in double decomposition).
