ZIMSEC O-Level Chemistry Paper 1 November 2022 Question Paper

ZIMBABWE SCHOOL EXAMINATIONS COUNCIL

General Certificate of Education Ordinary Level **CHEMISTRY** 4024/1 **PAPER 1 Multiple Choice**

**NOVEMBER 2022 SESSION** 1 hour

Additional materials: Multiple Choice answer sheet Soft clean eraser Soft pencil (type B or HB is recommended) Electronic calculator

TIME 1 hour

INSTRUCTIONS TO CANDIDATES

Do not open this booklet until you are told to do so. Write your name, centre number and candidate number on the answer sheet in the spaces provided unless this has already been done for you. There are forty questions in this paper. Answer all questions. For each question, there are four possible answers, A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate answer sheet.

Read very carefully the instructions on the answer sheet.

INFORMATION FOR CANDIDATES

Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. A copy of the Periodic Table is printed on page 15.

This question paper consists of 15 printed pages and 1 blank page. Copyright: Zimbabwe School Examinations Council, N2022.

Question 1

Which gas has the smallest rate of diffusion?

A methane

B ammonia

C carbon dioxide

D hydrogen chloride

Question 2

Drops of bromine liquid were placed at the bottom of a glass jar as shown in the diagram. After several hours the vapour spread to fill both jars uniformly as shown in the second diagram.

Which action will speed up the process?

A increasing the temperature

B lowering the temperature

C using a heavier isotope of bromine

D using solid bromine

Question 3

Purity of a substance can be tested by

A crystallisation.

B chromatography.

C filtration.

D precipitation.

Question 4

What happens to the oxidation number of nickel when nickel ore, NiS, is changed to pure nickel?

A increases to +1

B decreases to zero

C decreases to +2

D increases to zero

Question 5

What is the volume occupied by three moles of carbon dioxide at r.t.p?

A \(24 dm^3\)

B \(28 dm^3\)

C \(72 dm^3\)

D \(84 dm^3\)

Question 6

The chemical formula \(2 NH_3\) represents

A six molecules of hydrogen.

B two molecules of ammonia.

C two molecules of nitrogen.

D two atoms of ammonia.

Question 7

Ammonia gas reacts with dilute hydrochloric acid as shown in the equation:

\[ NH_{3(g)} + HCl_{(aq)} \longrightarrow NH_4Cl_{(aq)} \]

What mass of ammonium chloride is formed if 8.5 g of ammonia gas is used?

A \(2.70 g\)

B \(4.25 g\)

C \(8.50 g\)

D \(26.75 g\)

Question 8

Lathering of soap is a test for the

A purity of water.

B acidity of water.

C hardness of water.

D alkalinity of water.

Question 9

Which is not a reason for electroplating metals?

A decorating

B protecting

C improving purity

D improving electrical conductivity

Question 10

Which method of waste disposal is a source of carcinogens?

A bio-digestion

B incineration

C recycling

D landfilling

Question 11

The correct order of preparing some salts from a metal and an acid is

A crystallisation → evaporation → displacement → filtration.

B displacement → filtration → evaporation → crystallisation.

C evaporation → crystallisation → filtration → displacement.

D filtration → evaporation → displacement → crystallisation.

Question 12

The pH values of four solutions, W, X, Y and Z, are shown in the table.

| solution | pH | | :---: | :---: | | W | 3 | | X | 5 | | Y | 7 | | Z | 11 |

Which solution can be used to neutralize an acidic soil?

A W

B X

C Y

D Z

Question 13

What is observed when aqueous lead (II) nitrate reacts with sodium iodide?

A a cream precipitate

B a white precipitate

C a yellow precipitate

D a brown precipitate

Question 14

The diagram shows the positions of four elements in the periodic table represented by the letters W, X, Y and Z.

Which element, W, X, Y or Z forms an acidic oxide?

A W

B X

C Y

D Z

Question 15

Which element is least reactive?

A Fe

B Mg

C Na

D Zn

Question 16

The main function of limestone in the blast furnace is to

A oxidise iron ore.

B reduce iron ore.

C remove impurities.

D remove excess carbon.

Question 17

Which gas can be removed from the exhaust gases by a catalytic convertor?

A carbon dioxide

B carbon monoxide

C hydrocarbons

D sulphur trioxide

Question 18

Which statement is true about the use of plants in traditional medicine?

A there are clear prescriptions and dosages

B they can improve the health of a person

C they are not poisonous

D they do not cause any allergies

Question 19

One of the products of heating methane in excess oxygen is

A carbon

B soot

C carbon monoxide

D carbon dioxide

Question 20

Which structure represents an isomer of butane?

Question 21

A hydrocarbon, X, can crack as shown

What could be X?

A \(C_6 H_{14}\)

B \(C_8 H_{18}\)

C \(C_{10} H_{22}\)

D \(C_{16} H_{36}\)

Question 22

Which molecular formula could be that of candle wax?

A \(C_4 H_{10}\)

B \(C_6 H_{12}\)

C \(C_8 H_{18}\)

D \(C_{20} H_{42}\)

Question 23

The reaction between an alkene and bromine in the dark is

A an addition reaction.

B an oxidation reaction.

C a reduction reaction.

D a polymerisation reaction.

Question 24

An organic compound Q reacted with one mole of hydrogen in the presence of a catalyst.

What could be Q?

A an alcohol

B a carboxylic acid

C an alkene

D an alkane

Question 25

The graph was drawn from data obtained by heating water from \(-15^\circ C\) to \(100^\circ C\).

In which section of the graph is a mixture of ice and liquid water found?

Question 26

The apparatus shown was used to investigate the rate of diffusion of ammonia gas and hydrogen chloride. A white ring was observed after a few minutes.

At which point was the white ring observed?

Question 27

The diagram shows an electrochemical cell.

What is observed when the switch is closed?

A Bubbles of gas are formed on the zinc electrode.