myUASARevision for UASA
More
My progress
Chemistry questions, chapter 5
Nama / NameKelas / ClassTarikh / Date

Consumer and industrial chemistry

46 marks. Use Practice to check each answer as you go, or Exam to answer everything against the clock first.

Section A: objective questions

14 marks
Choose the best answer for each question.
1

Question 1

Oils and fats are esters formed from the reaction between
Show answerHide answer
A
Oils and fats are esters of fatty acids and glycerol (propane-1,2,3-triol).
For the teacher: Remembering, low difficulty, standard 5.1
Textbook p. 166
2

Question 2

Which statement is true of fats compared with oils?
Show answerHide answer
C
Fats come mainly from animals, are solid and have a high melting point because of saturated fatty acids.
For the teacher: Understanding, low difficulty, standard 5.1
Textbook p. 166
3

Question 3

What is the catalyst used in the hydrogenation of unsaturated oil?
Show answerHide answer
D
Hydrogen gas is passed into hot oil with nickel as catalyst.
For the teacher: Remembering, low difficulty, standard 5.1
Textbook p. 167
4

Question 4

Why is margarine, made from vegetable oil, solid at room temperature?
Show answerHide answer
C
Adding hydrogen saturates the chain, increases molecular mass and raises the melting point.
For the teacher: Understanding, medium difficulty, standard 5.1
Textbook p. 167
5

Question 5

Which is the general formula of a soap?
Show answerHide answer
D
Soap is the sodium (or potassium) salt of a fatty acid, RCOO−Na+.
For the teacher: Remembering, low difficulty, standard 5.2
Textbook p. 169
6

Question 6

The hydrolysis of an oil using concentrated sodium hydroxide is called
Show answerHide answer
B
Alkaline hydrolysis of oils or fats to give soap and glycerol is saponification.
For the teacher: Remembering, low difficulty, standard 5.2
Textbook p. 170
7

Question 7

Which part of a soap anion dissolves in grease?
Show answerHide answer
C
The long hydrocarbon (hydrophobic) chain dissolves in grease; the COO− end is hydrophilic.
For the teacher: Remembering, low difficulty, standard 5.2
Textbook p. 173
8

Question 8

Soap is less effective than detergent in hard water because soap
Show answerHide answer
A
Soap anions combine with Ca2+ and Mg2+ to form insoluble scum; detergent salts stay soluble.
For the teacher: Understanding, medium difficulty, standard 5.2
Textbook p. 174
9

Question 9

Sodium benzoate is added to tomato sauce as a
Show answerHide answer
B
Sodium benzoate prevents the growth of bacteria and fungi.
For the teacher: Remembering, low difficulty, standard 5.3
Textbook p. 177
10

Question 10

Which additive and function are correctly matched?
Show answerHide answer
C
Pectin is a stabiliser that gives jams a uniform texture. Lecithin is an emulsifier, aspartame a flavouring, ascorbic acid an antioxidant.
For the teacher: Understanding, medium difficulty, standard 5.3
Textbook p. 178
11

Question 11

A patient with a bacterial infection should be given
Show answerHide answer
B
Penicillin is an antibiotic (antimicrobial) that kills bacteria.
For the teacher: Understanding, low difficulty, standard 5.4
Textbook p. 182
12

Question 12

Which is NOT a basic ingredient of cosmetics?
Show answerHide answer
A
Basic cosmetic ingredients are water, emulsifiers, thickeners, dyes, moisturisers, preservatives and fragrances. Sodium hypochlorite is a bleach and is not a cosmetic ingredient.
For the teacher: Remembering, low difficulty, standard 5.4
Textbook p. 185
13

Question 13

The size of nanoparticles lies in the range of
Show answerHide answer
B
Nanoscale is between 1 nanometre and 100 nanometres.
For the teacher: Remembering, low difficulty, standard 5.5
Textbook p. 187
14

Question 14

In the electrocoagulation of industrial wastewater, the pollutants are removed as
Show answerHide answer
D
Pollutants form flocs, which are separated and removed as sludge.
For the teacher: Understanding, low difficulty, standard 5.6
Textbook p. 193

Section B: structured questions

32 marks
Answer all questions.
15

Question 15

Oils and fats are made from fatty acids and glycerol.
[1 mark] (a)Name the homologous series of oils and fats.
Show answerHide answer
Tick each point you got.
[2 marks] (b)Palm oil is liquid but butter is solid at room temperature. Explain the difference.
Show answerHide answer
Tick each point you got.
[2 marks] (c)Name the process that changes palm oil into margarine and state the catalyst.
Show answerHide answer
Tick each point you got.
For the teacher: Understanding, low difficulty, standard 5.1
Textbook p. 166
16

Question 16

Soap can be prepared in the laboratory by heating palm oil with concentrated alkali.
[1 mark] (a)Name the reaction.
Show answerHide answer
Tick each point you got.
[2 marks] (b)Name the two products when palm oil reacts with concentrated sodium hydroxide.
Show answerHide answer
Tick each point you got.
[2 marks] (c)Write the equation for the reaction of palmitic acid, C15H31COOH, with sodium hydroxide.
Show answerHide answer
Tick each point you got.
For the teacher: Understanding, low difficulty, standard 5.2
Textbook p. 170
17

Question 17

Cleaning agent A has the anion CH3(CH2)11OSO3− and cleaning agent B has the anion CH3(CH2)16COO−. In hard water, A removes greasy stains completely but some stains remain with B.
[2 marks] (a)State the type of cleaning agent A and B.
Show answerHide answer
Tick each point you got.
[2 marks] (b)Explain why B is less effective in hard water.
Show answerHide answer
Tick each point you got.
For the teacher: Analysing, high difficulty, standard 5.2
Textbook p. 175
18

Question 18

Describe the cleansing action of soap on a greasy cloth.
[2 marks] (a)State the roles of the hydrophilic and hydrophobic parts.
Show answerHide answer
Tick each point you got.
[2 marks] (b)Explain why the grease droplets do not return to the cloth.
Show answerHide answer
Tick each point you got.
For the teacher: Understanding, low difficulty, standard 5.2
Textbook p. 173
19

Question 19

The label on a margarine pack reads: vegetable oil, salt, emulsifier, ascorbic acid, flavouring and permitted dyes.
[2 marks] (a)What type of additive is ascorbic acid and what is its function?
Show answerHide answer
Tick each point you got.
[1 mark] (b)State the function of the emulsifier.
Show answerHide answer
Tick each point you got.
[1 mark] (c)Give one reason why food additives must be used in controlled amounts.
Show answerHide answer
Tick each point you got.
For the teacher: Understanding, low difficulty, standard 5.3
Textbook p. 178
20

Question 20

Ali stopped taking the antibiotic given by his doctor after two days because he felt better.
[2 marks] (a)Explain why this is not advisable.
Show answerHide answer
Tick each point you got.
[1 mark] (b)Name one side effect of long-term use of corticosteroids.
Show answerHide answer
Tick each point you got.
For the teacher: Evaluating, medium difficulty, standard 5.4
Textbook p. 183
21

Question 21

Graphene is a nanomaterial.
[1 mark] (a)What is graphene?
Show answerHide answer
Tick each point you got.
[2 marks] (b)State two physical properties of graphene.
Show answerHide answer
Tick each point you got.
[1 mark] (c)Explain why graphene is suitable for water filtration membranes.
Show answerHide answer
Tick each point you got.
For the teacher: Remembering, low difficulty, standard 5.5
Textbook p. 190
22

Question 22

A factory discharges wastewater containing mercury and lead into a river.
[1 mark] (a)Why is this wastewater harmful?
Show answerHide answer
Tick each point you got.
[2 marks] (b)Describe how electrocoagulation treats the wastewater.
Show answerHide answer
Tick each point you got.
For the teacher: Evaluating, medium difficulty, standard 5.6
Textbook p. 193