ZIMSEC O-Level Chemistry Paper 1 November 2020 Question Paper

ZIMBABWE SCHOOL EXAMINATIONS COUNCIL General Certificate of Education Ordinary Level

**CHEMISTRY** **PAPER 1 Multiple Choice**

**NOVEMBER 2020 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.

Question 1

The table shows information about the subatomic particles of two species, \(X\) and \(Y\).

| element | number of electrons | number of neutrons | number of protons | | :---: | :---: | :---: | :---: | | \(X\) | 4 | 6 | 5 | | \(Y\) | 6 | 4 | 5 |

Which statement about \(X\) and \(Y\) is correct?

A They are both positively charged.

B They have the same mass number.

C They represent the same element.

D They are both negatively charged.

Question 2

What is the correct number of subatomic particles in the ion \({ }_{38}^{90} \mathrm{Z}^{2+}\)?

| | protons | neutrons | electrons | | :---: | :---: | :---: | :---: | | A | 38 | 52 | 40 | | B | 38 | 52 | 36 | | C | 52 | 38 | 40 | | D | 52 | 38 | 36 |

Question 3

The table shows information about particles of two elements, M and N.

| element | number of protons | number of neutrons | electronic structure | | :---: | :---: | :---: | :---: | | M | 9 | 10 | 2.8 | | N | 17 | 20 | 2.8.8 |

Which statement is correct for both M and N?

A They are isotopes of the same element.

B They are negatively charged ions.

C They are atoms of noble gases.

D They are positively charged ions.

Question 4

Which factor affects the rate of diffusion of a gas?

A inertness

B solubility

C colour

D molecular mass

Question 5

Increasing the temperature of a reaction mixture increases the rate of reaction because

A particles gain kinetic energy and collide more frequently.

B particles lose kinetic energy and collide less frequently.

C particles gain kinetic energy and collide less frequently.

D particles lose kinetic energy and collide more frequently.

Question 6

Which statement is not true about the properties of particles of matter?

A particles in a liquid have less energy than particles in a gas

B particles in a solid have less energy than particles in a liquid

C particles in a gas have less energy than particles in a solid

D particles in a liquid have more energy than particles in a solid

Question 7

An element, X, in its ground state, is a diatomic gas and has seven valence electrons.

Element X is

A helium.

B oxygen.

C chlorine.

D nitrogen.

Question 8

A volume of \(20.00 \mathrm{~cm}^{3}\) of \(0.20 \mathrm{moldm}^{-3}\) hydrochloric acid were reacted with potassium hydroxide solution.

What was the concentration of the hydroxide if \(15.00 \mathrm{~cm}^{3}\) were needed for complete neutralisation?

A \(0.27 \mathrm{moldm}^{-3}\)

B \(1.33 \mathrm{moldm}^{-3}\)

C \(4.00 \mathrm{moldm}^{-3}\)

D \(0.03 \mathrm{moldm}^{-3}\)

Question 9

Which statement is not correct about the reaction between calcium carbonate and excess hydrochloric acid?

A The reaction can be speeded up by using powdered calcium carbonate.

B The reaction can be slowed down by using cold acid.

C The reaction can be speeded up by using dilute acid.

D Half the volume of gas is produced if half the mass of calcium carbonate is used.

Question 10

Which set of elements exist as diatomic molecules?

Question 11

An endothermic reaction occurs when

A the products are more stable than the reactants.

B the reactants have more energy than the products.

C bonds are formed.

D bonds are broken.

Question 12

An ionic compound has the formula \(\mathrm{MX}_{2}\).

Which row correctly shows the Groups of the Periodic Table to which the elements represented by M and X belong?

| | M | X | | :---: | :---: | :---: | | A | VII | II | | B | II | VII | | C | I | III | | D | VI | III |

Question 13

Which statement is not true about eutrophication?

A It is caused by washing of excess fertilizers into water bodies.

B It results in increased growth of algae and other aquatic plants.

C It reduces the amount of oxygen available to fish and other aquatic animals.

D It can be reversed by reducing the number of organisms that need oxygen.

Question 14

Extraction of copper consists of four main stages.

What is the correct sequence of these stages?

A crushing, flotation, smelting, electrolysis

B smelting, crushing, flotation, electrolysis

C electrolysis, smelting, crushing, flotation

D flotation, crushing, smelting, electrolysis

Question 15

Hydrogen gas is becoming very popular as a fuel mainly because hydrogen

A is very flammable.

B is more efficient.

C is cheaper to produce.

D produces less pollutants.

Question 16

The gas produced at the anode, during the electrolysis of dilute sulphuric acid, can be identified by

A dipping a burning wooden splint into the gas.

B dipping damp blue litmus paper into the gas.

C bubbling the gas through limewater.

D dipping a glowing wooden splint into the gas.

Question 17

An organic compound has \(92.3\%\) carbon and \(7.7\%\) hydrogen by mass. The empirical formula of the compound is

A \(\mathrm{C}_{3} \mathrm{H}_{5}\).

B \(\mathrm{C}_{2} \mathrm{H}_{3}\).

C \(\mathrm{CH}_{2}\).

D CH.

Question 18

When chlorine gas is bubbled through a colourless solution of sodium bromide, the mixture turns reddish brown because

A chlorine gas is red in solution.

B chlorine is displaced from the solution.

C bromine is displaced from the solution.

D the two elements have the same reactivity.

Question 19

The equation for the reduction of iron oxide by carbon monoxide in the blast furnace is:

\[ \mathrm{Fe}_{2} \mathrm{O}_{3(s)}+3 \mathrm{CO}_{(g)} \longrightarrow 2 \mathrm{Fe}_{(s)}+3 \mathrm{CO}_{2(g)} \]

What mass of iron oxide is needed to produce 56 g of pure iron?

A 80 g

B 112 g

C 160 g

D 320 g

Question 20

Which reaction is not a redox reaction?

A \(2 \mathrm{Fe}+3 \mathrm{Cl}_{2} \longrightarrow 2 \mathrm{FeCl}_{3}\)

B \(2 \mathrm{FeCl}_{2}+\mathrm{Cl}_{2} \longrightarrow 2 \mathrm{FeCl}_{3}\)

C \(\mathrm{Fe}+2 \mathrm{HCl} \longrightarrow \mathrm{FeCl}_{2}+\mathrm{H}_{2}\)

D \(\mathrm{Fe}_{2} \mathrm{O}_{3}+6 \mathrm{HCl} \longrightarrow 2 \mathrm{FeCl}_{3}+3 \mathrm{H}_{2} \mathrm{O}\)

Question 21

Which process is not done during the extraction of nickel?

A electrolysis of nickel chloride with impure nickel as the anode

B electrolysis of nickel chloride with impure nickel as the cathode

C roasting the sulphide ore to get the oxide

D reacting the impure nickel with carbon monoxide

Question 22

Ship bodies made of steel can be prevented from corrosion by fixing a block of another metal to the ship body.

Which metal would not prevent corrosion if used?

A copper

B magnesium

C aluminium

D zinc

Question 23

What is the best way of obtaining water from a salt solution?

A evaporation

B simple distillation

C decanting

D fractional distillation

Question 24

Ethanoic acid reacts with ethanol to form ethyl ethanoate.

Which row gives the correct name of the reaction and the correct condition for the reaction?

| | reaction | condition | | :---: | :--- | :--- | | A | esterification | acidic | | B | neutralisation | acidic | | C | esterification | alkaline | | D | neutralisation | alkaline |

Question 25

Which substance is not suitable for the removal of a salt cake deposited on the element of a kettle by hard water?

A dilute hydrochloric acid

B vinegar

C lemon juice

D bicarbonate solution

Question 26

What problem is associated with the incineration of refuse on a large scale?

A increases eutrophication

B an increase in acid rain

C increases costs

D ozone layer thickens

Question 27

The equation for the complete combustion of butane is:

\[ \mathrm{C}_{4} \mathrm{H}_{10}+\frac{13}{2} \mathrm{O}_{2} \longrightarrow 4 \mathrm{CO}_{2}+5 \mathrm{H}_{2} \mathrm{O} \]

What volume of carbon dioxide is produced from the complete combustion of 58 g of butane at r.t.p?