4024q2Specimen paper

Extracted Content: 4024q2Specimen paper

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For Performance Mecsurement

ZIMBABWE SCHOOL EXAMINATIONS COUNCIL

General Certificate of Education Ordinary Level

CHEMISTRY4024/2
PAPER 2 Theory

SPECIMEN PAPER 1 hour 45 minutes

Candidates answer on the question paper.
Additional materials:Electronic calculator

Allow candidates 5 minutes to count pages before the examination
This booklet should not be punched or stapled and pages should not be removed.
TIME 1 hour 45 minutes

INSTRUCTIONS TO CANDIDATES

Write your name, Centre number and candidate number in the spaces at the top of this page
and centre number and candidate number on top of the right corner of every page of this
paper. Check if the booklet has all the pages and ask the invigilator for a replacement if there
are duplicate or missing pages.

Section A

Answer all questions.

Write your answers in the spaces provided on the question paper.
Section B

Answer any four questions.

Write your answers on the spaces provided on the question paper
Do not fasten the booklet

INFORMATION FOR CANDIDATES
The number of marks is given in brackets [ ] at the end of each question or part question paper.

A copy of the periodic table is on page 20.

This question paper consists of 20 printed pages.

Copyright: Zimbabwe School Examinations Council, Specimen paper.

OZIMSEC [Turn over

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Section A

Answer all the questions in the spaces provided.

(a) _ A student prepared a blue solution, P, by adding black copper (II) oxide
powder to nitric acid as shown in Fig.1.1.

black copper (11)
oxide powder

nitric acid blue solution P

Fig.1.1

@ Name two chemical substances in the blue solution.

ii) State two observations made by the student.

(iii) © Write a balanced chemical equation for the reaction.

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Write a balanced chemical equation for the reaction that will
occur when

@ zinc granules are added to copper sulphate solution,

ii) calcium carbonate is heated strongly.

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(a) _ Ina titration, 25 cm? of aqueous ammonia required 21.50 cm? of

0.1 mol dm® sulphuric acid for complete neutralisation. The
equationfor the reaction is:

HSO jyq)+2NH,OH ,.) > (NH, ), SO gyq) +2110 fa)

4laq

@ Calculate the number of moles of sulphuric acid in 21.50 cm?
of the solution.

[2]

ii) Deduce the number of moles of ammonia in the 25 cm?
of ammonia.

(iii) Calculate the concentration of the ammonia solution.

ob) @& Give one physical property in which the oxides, CO2 and
S02, are similar.

(ii) Name the industrial process by which CO2q) is obtained
from air.

_oo ee [1]
[Total :8]

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(b)

Table. 3.1 showssome of the gaseous pollutants.

Complete Table 3.1 by stating a use and an effect of the gases on
the environment.

gas

use

effect on the environment

CO,

S02

Explain why no chemical reaction takes place when

09) aluminium powder that has been exposed to air is added
to a solution of iron (II) sulphate,

ii) magnesium powder is added to a solution of calcium

chloride,

(iii) zinc oxide is heated in a stream of hydrogen,

(iv) carbon dioxide is bubbled through a solution of
hydrochloric acid.

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[1]

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Fig.4.1 shows how an organic compound, Q,is produced
from ethene.

H H
\ 7% qt
C=C |
/ \ reagent x ~C—C-—OoH
catalyst ||
H H HH
ethene P
atmospheric
oxygen
Q
Fig.4.1
@ Name
1. reagentxX,
2. compoundP, [2]

ii) Draw the displayed structural formula of Q.

(iii) Give anytwo uses of P.

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(b) Fig.4.2 shows the structure of a protein molecule.

" 7 i i
N FF CoN —Ez7t— CON aaa Cc
H H
Fig.4.2

@ Name the smaller units (monomers) that make up the
protein molecule.

ii) Describe how the protein molecule can be broken down
into the smaller units.

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lid

chromatography.
paper

solvent
front

container

solvent

Fig.5.1

(a) 09) State the number of dyes in ink M.

ii) Describe one difference and one similarity between
inks in samples 1 and 3.

difference

similarity

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(a) (iii) Identify with reasons the sample ink that could have
been used to write the bad message.

(b) @ Name one property that determines the distance travelled
by a dye in chromatography.

09) The solvent travelled 8.0 cm and the dye in ink 3
travelled 3.0 cm.

Calculate the R¢ value of the dye into 3.

(iii) State the importance of R¢ values.

(c) Explain why the container in Fig.5.1 was covered.

[Total: 8]

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Section: B
Answer any four questions from this section.

(a) Define the term ionic bonding.

(b) The table shows some physical properties of three compounds.

compound electrical conductivity melting point
naphthalene does not conduct low
copper (I]) good conduction when in high
chloride solution
ethane does not conduct low

09) Explain why

1. copper (II) chloride has a higher melting point than
ethane,

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(b) ii) Describe and explain what happens when

1. solid naphthalene is added to water,

2. an electric current is passed through a concentrated
solution of copper (II) chloride

oe [2]
( Element X has 9 protons and 10 neutrons.
09) Draw a diagram showing the full electronic structure of X,
@ State two physical properties of the compound formed
when X reacts with sodium
5
0 [2]
[Total:15]

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(a) Cast iron from the blast furnace contains 4 to 5 % carbon and
other impurities.

@ Name one other impurity in cast iron.

(ii) Describe how the impurities are removed in the oxygen
lance furnace.

(b) The structural formulae of butenedioic acid is shown in Fig. 7.1.

o HH 9g
\ | y/,
—c=c-€
HO OH
Fig. 7.1

09) Give the empirical formulae of butenedioicacid

ii) Describe how butenedioic acid reacts with

1. aqueous bromine
oe [1
2. sodium carbonate
oe [1
3. Magnesium
[1

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(©)

13

(iii) Draw the structural formula of the product formed when
butenedioic acid reacts with bromine.

[1]

Fig.7.2 shows the reaction ofethene molecules to produce N.

H H
Nc = ne —> product N
a \
H H fa
Fig. 7.2

@ Name

1. this type of reaction,

2. product N,

ii) Draw the displayed structural formula of N.

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(a)

14

(iii) State any two uses of the product N.

(iv) Describe how productN can be safely disposed from
the environment.

oe [3]
[Total:15]
Describe how a pure sample of sodium chloride can be prepared
fromsolutions of hydrochloric acid and sodium hydroxide of
known concentrations.
[4]

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15

Fig.8.1 shows chemical tests carried out on a salt to identify the
ionspresent in the salt.

colourless solution|

of the salt dilute

HNO,

and
aqueous Ba(NO, ),

bubbles of
gas given
off

white precipitate
formed
white

excess aqueous precipitate
NaOH

colourless
solution
formed

Fig.8.1
09) Deduce the cations and anions in the salt.
cations

anions

ii) Iodide ions were suspected to be present in the salt.

Describe a chemical test and observations to show the
presence of the iodide ions.

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(c) _ A student placed a few calcium granules in a flask containing cold water
coloured with universal indicator. The gas given off was collected in a
measuring cylinder inverted in water as shown in Fig. 4.

water
+

universal

indicator

calcium
granules
Fig. 4
( 09) State and explain any one observable change that occurs in the
flask.
observation
explanation,
oe [2]
(ii) Name the gas produced.
oe [1]
(iii) | Describe a test for the gas produced.
oe [1]
[Total:15]

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Fig.5 shows the main steps in the manufacture of sulphuric acid.

sulphur waste
water BASCS
LB [> |
dry air
0, coneentrated H SO,

Fig.5

(a) @ Choose from the letters A - E, the box that would be labelled

1. catalytic converter,
2. chimney,
3. purifier.

(ii) Identify one error on the flow diagram and describe how
this can be corrected.

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(a)

(b)

(a)

18

(iii) State any one condition used in C and write the overall
equation for the reaction which takes place.

condition

Describe how sulphuric acid is converted into ammonium
sulphate fertilizer.

oo [3]
[Total:15]

@ two different physical properties of bromine and iodine.

ii) two similar chemical chemical properties of bromine
and iodine.

(iii) any two uses of chlorine.

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(b)

19

Chlorine reacts with potassium bromide as shown.

2KBr(aq) + Cly(g) > 2KCl aq) + Brag)

09) State one observation made as the reaction occurs.

(ii) | Name this type of reaction giving a reason for your answer.

type of reaction

Explain why

09) incineration is a controversial method of waste disposal

ii) the use of landfills as method of waste disposal is being
discharged.

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DATA SHEET

The Periodic Table of the Elements

Group
I Ul Ill IV v vi Vil e}
1 4
H He
Hydrogen Helium
1
7 9 an 12 14 16 19 20
Li Be B c N oO F Ne
him Beryum Boron Carbon trogen Onygen Fuorine Neon
4 6 8 9 10
23 24 27 28 PT 32 355 40
Na Mg Al Si P s cl Ar
Sodium — | Magnesium ‘Aluminium sicon | Phosphorus | Sulphur hioina ‘Argon
2 13 14 16 16 18
39 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 a4
K Ca Sc Ti Vv Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Potassium Calcium ‘Scandium Titeniurn Vanadium | Chromium | Manganese tron Cobatt Nickol Copper Zine Gallium, Germanium Arsenic Selenium Bromide Krypton
19 20 24 2 23 24 28 26 27 28 29 30 31 32 3 35 36
85 88 89 ot 93 96 101 103 106 108 112 115 119 122 128 127 131
Rb sr Y 2r Nb Mo Te Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Rubidium | Stronium rum Zirconium | Niobium — | Molybdenum | Technetiom | Ruthenium | Rhodium Pallsium siver Cadmium indium Tin santimery | Tetum todine Xenon
37 38 39 40 44 42 43 4 45 46 47 49 50 62 53 54
133 137 139 178 181 184 186 190 192 195 197 201 204 207 209
Cs Ba La Hf Ta Ww Re Os Ir Pt Au Hg Tl Pd Bi Po At Rn
Caesium Barium Lanthanum Hafnium ‘Tantalum Tungsten Rhenium ‘Osmium: rigium Platinum Gold ‘Mercury Thallium Lead Bismuth Polonium stating Radon
55 56 57 *| 72 73 74 75 76 7 78 79 80 81 82 83 85 86
226 227
Fr Ra Ac
Frencium | Radium Atrium
87 88 89
+ . 140 141 144 150 152 187 159 162 165 167 169 173 175
*58-71 Lanthanoid series
190-103 Actinoid seri Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
- ctinold series Cerium — | Praseodymium | Neodymium | Promethium | Samarium Europlum Gadolinium Terbium Dysprosium | Holmium Erbium Thutium Ytterbium Lutetium
58 59 61 62 63 65 66 ov 68 69 70 cal
a a = relative atomic mass 232 238
Key x XE atomic symbol Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
- . Thorium | Protactiium | uranium | Neptuniom | Plutonium | Ameriium curum | Berketum | caiforsum | cinstenium | —ermium | Mendelevium | Nobefum | Lawrencium
b » = proton (atomic) Number 90 ot 92 93 94 96 a7 98 99 101 102 103

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The volume of one mole of any gas is 28 dm’ at room temperature and pressure (r.t.p.)

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