CIE iGCSE Co-Ordinated Science C11.6 Alcohols Exam Style Questions Paper 3
Question
(a) Choose from the following substances to answer the questions.
Each substance may be used once, more than once or not at all.
(i) Used as a chemical test for water.
(ii) Used as a solvent.
(iii) Used in aircraft parts.
(iv) Used in the manufacture of sulfuric acid.
(v) Used in the treatment of the water supply.
(vi) Used in the treatment of acidic soil.
(b) Sulfuric acid has the formula H$_{2}$SO$_{4}$.
(i) State the total number of atoms in one molecule of sulfuric acid.
(ii) State the total number of different elements found in one molecule of sulfuric acid.
(c) A student reacts magnesium with dilute sulfuric acid.
The equation for the reaction is shown.
Mg(s) + H$_{2}$SO$_{4}$(aq) MgSO$_{4}$(aq) + H$_{2}$(g)
(i) State the names of the two products of the reaction.
(ii) State the separation technique used by the student to remove any unreacted solid magnesium from the reaction mixture.
▶️Answer/Explanation
Ans : 2(a)(i) copper sulfate ;
2(a)(ii) ethanol ;
2(a)(iii) aluminium ;
2(a)(iv) sulfur ;
2(a)(v) chlorine ;
2(a)(vi) limestone ;
2(b)(i) 7 ;
2(b)(ii) 3 ;
2(c)(i) magnesium sulfate ;
hydrogen ;
2(c)(ii) filtration ;
Question
Ethanol has the formula C2H5OH.
(a) State the number of different elements in one molecule of ethanol.
(b) Complete Fig. 8.1 to show the structure of ethanol.
(c) State two ways of producing ethanol.
1 …………………………………………………………………………
2 …………………………………………………………………………
(d) Complete the word equation for the complete combustion of ethanol.
ethanol + ………………………….. →………………………….. + …………………………..
(e) Explain why ethanol is not a hydrocarbon.
(f) Ethanol is used in alcoholic drinks.
State one other use for ethanol.
▶️Answer/Explanation
Ans : 8(a) 3 ;
8(b) 
C-O-H ;
all else correct ;
8(c) fermentation ;
reaction of ethene with steam / water ;
8(d) oxygen ;
carbon dioxide and water ;
8(e) contains oxygen ; 1
8(f) solvent / fuel ;
Question
Petroleum is a raw material for the production of useful substances.
Fig. 8.1 shows three processes, X, Y and Z, used to make ethanol.
(a) Identify process X and process Y.
process X ………………………………………………………………………………………………………………….
process Y ………………………………………………………………………………………………………………….
(b) State the substance added to ethene during process Z to make ethanol.
…………………………………………………………………………………………………………………………………
(c) Ethene is a hydrocarbon.
Explain why ethene is described as a hydrocarbon.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(d) State the two products of the complete combustion of ethene.
1 ………………………………………………………………………………………………………………………………
2 ………………………………………………………………………………………………………………………………
(e) Complete Fig. 8.2 to show the structure of an ethanol molecule, C2H5OH. Include all the atoms and bonds.
Fig. 8.2
▶️Answer/Explanation
Ans: 8(a) process X – fractional distillation ;
process Y – cracking ;
8(b) steam ;
8(c) contains carbon and hydrogen (atoms) ;
only ;
8(d) carbon dioxide ;
water ;
8(e)
O – H attached to carbon ;
all else correct ;
Question
Petroleum is a raw material for the production of useful substances.
Fig. 8.1 shows three processes, X, Y and Z, used to make ethanol.
(a) Identify process X and process Y.
process X ………………………………………………………………………………………………………………….
process Y ………………………………………………………………………………………………………………….
(b) State the substance added to ethene during process Z to make ethanol.
…………………………………………………………………………………………………………………………………
(c) Ethene is a hydrocarbon.
Explain why ethene is described as a hydrocarbon.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(d) State the two products of the complete combustion of ethene.
1 ………………………………………………………………………………………………………………………………
2 ………………………………………………………………………………………………………………………………
(e) Complete Fig. 8.2 to show the structure of an ethanol molecule, C2H5OH. Include all the atoms and bonds.
Fig. 8.2
▶️Answer/Explanation
Ans: 8(a) process X – fractional distillation ;
process Y – cracking ;
8(b) steam ;
8(c) contains carbon and hydrogen (atoms) ;
only ;
8(d) carbon dioxide ;
water ;
8(e)
O – H attached to carbon ;
all else correct ;