1Self-assessment practice test 2© Cambridge University Press IGCSE Chemistry

Self-assessment practice testsTest 2 – Material from Chapters 5–8 | 45 minutes

1 Metals and non-metals generally produce diff erent types of oxides when reacted with air or oxygen. Which row in the table correctly lists the nature of two elements’ oxides?

Forms an acidic oxide Forms a basic oxide

A phosphorus sulfur

B magnesium sulfur

C sulfur phosphorus

D sulfur magnesium

2 Th e growth of plants can be signifi cantly aff ected by the pH of the soil. Th e table below shows the pH range over which a plant takes up nutrients from fertilisers.

Nutrient pH range

nitrogen (N) 6.0 to 8.0

phosphorus (P) 6.5 to 7.5

potassium (K) 7.0 to 8.0

Over which pH range does the plant take up all three nutrients?

A 5.0 to 6.0B 7.0 to 7.5C 6.0 to 6.5D 7.5 to 8.0

3 A compound is a salt if it

A can neutralise an acid.B is a product of the reaction between an acid and a base.C contains more than one element.D dissolves in water.

4 Which of the following substances can neutralise hydrochloric acid?

A waterB litmus solutionC carbon dioxideD ammonia

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5 Th e growth of plants can be signifi cantly aff ected by the pH of the soil. Th e diagram shows the results of a pH test on a sample of garden soil.

3 4

soil reading

5 6 7pH

8 9 10 11

What could be added to the soil to bring its pH back up to 7?

A sandB limeC hydrochloric acidD potassium chloride

6 Which of the following reacts with dilute hydrochloric acid to produce hydrogen gas?

A copperB chlorineC carbonD zinc

7 Th e method of salt preparation in the laboratory has certain clear stages. Which three steps are needed to make sodium sulfate crystals from sodium hydroxide solution and dilute sulfuric acid?

First step Second step Third step

A evaporation crystallisation neutralisation

B neutralisation evaporation crystallisation

C neutralisation crystallisation evaporation

D evaporation neutralisation crystallisation

8 Which of the following properties is common to all acids?

A Th eir aqueous solutions have a pH greater than 7.B Th ey are solid at room temperature.C Th ey react with bases.D Th ey react with copper to give hydrogen.

9 Which gas is released when magnesium reacts with hydrochloric acid?

A oxygenB carbon dioxideC hydrogenD chlorine

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10 Which pH change occurs when water dissolves an alkali such as sodium hydroxide?

A 7 → 1B 1 → 12C 1 → 7D 7 → 12

11 Certain gases are very soluble in water. Th ey dissolve to produce acidic or alkaline solutions. Th e graph shows the change in pH when a gas X was bubbled into water.

7

Time

pH

What could gas X be?

A ammoniaB sulfur dioxideC hydrogenD carbon dioxide

12 What is missing from the equation?

acid + base → salt + ………………

A carbon dioxideB waterC oxygenD hydrogen

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13 To help prevent damage to the environment it is important to treat industrial waste to avoid extremes of pH. Th e graph shows how the pH of an industrial waste changed when treated with substance X.

7

substance X added Time

pH

Which of the following must be substance X?

A coalB waterC limeD salt

14 Some air is polluted with sulfur dioxide from local industries. A sample of the polluted air is passed through water to dissolve the sulfur dioxide.

What is the pH of the solution formed and how does it aff ect litmus paper?

pH Effect on litmus paper

A above 7 red to blue

B below 7 blue to red

C above 7 blue to red

D below 7 red to blue

15 A company needs to build a storage tank to be used to store either water or dilute sulfuric acid. Which material cannot be used for making the tank?

A copperB glassC zincD poly(ethene)

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16 Various factors aff ect the rate of a chemical reaction. One of these is the surface area of a solid that is available to react when in contact with a liquid. A chemical reaction between pieces of a solid and an acid is very fast.

Which changes would make the reaction slower?

Acid Pieces of solid

A less concentrated larger

B more concentrated larger

C less concentrated smaller

D more concentrated smaller

17 Measuring the volume of gas produced against time for a reaction in which a gas is produced is one way of fi nding the rate of reaction. Th e speed with which a solid reacts with a solution to produce a gas can be measured by using the apparatus shown.

solution

syringe

solid

What essential item for carrying out the experiment is missing from the diagram?

A a thermometerB a balanceC a Bunsen burnerD a clock

18 A newspaper carries headlines and photographs about an explosion at a fl our mill. What factor could have increased the risk of such an explosion?

A opening the windowsB employing more staff in the millC grinding the fl our more fi nelyD adding salt to the fl our

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19 How can the rate of reaction between dilute hydrochloric acid and marble chips (calcium carbonate) be increased?

A by using a larger volume of acidB by making the acid more concentratedC by using larger marble chipsD by adding water to the acid to dilute it

20 Experiments were carried out on the factors that increased the rate of a particular reaction. In diff erent experiments, a catalyst is added to a reaction mixture and the temperature of the mixture is decreased. What is the eff ect of these changes on the rate of the reaction?

Catalyst added Temperature decreased

A faster slower

B slower faster

C faster faster

D slower slower

21 Dilute sulfuric acid is added to copper(II) oxide in the apparatus shown.

sulfuric acid

flask

copper(II) oxide

balance

Th e readings of the balance are taken aft er 30-second time intervals. Which graph shows how the balance reading changes during the reaction?

Mas

s

A B C D

0 0 Time

Mas

s

Mas

s

0 0

Mas

s

0 0 Time 0 Time 0 Time

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22 For a reaction that produces a gas the rate of reaction can be followed by measuring the amount of gas collected in a gas syringe with time. Th e graph below shows how the total volume of a gas given off from a reaction changes with time. In which time interval is least gas given off indicating that the reaction is slowest in that period?

Volu

me

of g

as

0 A B C D Time

23 Excess hydrochloric acid was added to calcium carbonate in two experiments and the volume of carbon dioxide gas produced was measured every minute. Th e graphs below show the results of the two experiments.

100

50

Volu

me

of g

as p

rodu

ced experiment 2

experiment 1

0 Time

When we compare experiment 1 and experiment 2, we can deduce that experiment 1 was carried out using

A a lower temperature.B larger pieces of calcium carbonate.C half as much calcium carbonate.D twice as much acid.

24 Four experiments were carried out on the reaction between zinc and nitric acid. Portions of powdered zinc are added to dilute nitric acid under the diff erent conditions.

In which experiment is the rate of reaction greatest at the beginning?

Experiment Temperature of acid / °C Concentration of acid

A 20 high

B 30 high

C 30 low

D 20 low

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25 A piece of zinc is placed in dilute sulfuric acid. Which change mentioned below would slow down the speed of reaction?

A adding a catalystB powdering the zincC heating the acidD adding water

26 Every atom has its own atomic mass, Ar . Th ese are added together to fi nd the relative formula mass, Mr , of a substance. Th e value for calcium carbonate, CaCO3, is 100.

What mass of carbon is present in 100 g of calcium carbonate?

A 12 g B 60 g C 48 g D 36 g

27 Butenedioic acid is a relatively complex acid molecule and it has the structure shown below.

O

O

O

C

C

C

C OH

HH

H

What is the molecular formula of butenedioic acid?

A CHOB C4H4O4

C C6H4O6

D C4HO2

28 For butenedioic acid, using the structure given above, what is its empirical formula?

A CHOB C2H2O2

C C3H2O3

D C4HO2

29 A molecule of the organic compound X contains the following:2 atoms of carbon, (C)2 atoms of oxygen, (O)4 atoms of hydrogen, (H).What is the empirical formula of X?

A (CH2)2OB (CH2)2O2

C C2(OH)4

D CH2O

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30 Arsenic is in the same group of the Periodic Table as nitrogen. It forms a compound with hydrogen just as nitrogen does. A molecule contains one atom of arsenic, As, and three atoms of hydrogen.What is the formula of this molecule?

A 3AsH B As3H C AsH3 D (AsH)3

31 Each element in the Periodic Table has its own chemical symbol. What are the correct symbols for the elements chlorine, nitrogen and potassium?

Chlorine Nitrogen Potassium

A Cl N K

B C Ni P

C Cl Ni P

D C N K

32 Ethanol has the formula shown below.

CH3CH2OHWhat is the relative molecular mass, Mr , of ethanol?

A 26 B 9 C 40 D 46

33 Th e diagram shows a blast furnace for extracting iron from hematite.

hematite + X + Y

waste gases

hot air iron

slag

What are X and Y?

X Y

A lime coal

B limestone coal

C lime coke

D limestone coke

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34 Metals have diff erent reactivities and this aff ects their method of extraction and the types of reaction they can take part in. Th e table below contains some information about the reactivity of three diff erent metals X, Y, and Z.

Metal Reaction with water or steam

Reaction with dilute hydrochloric acid

X reacts with cold water reacts with cold acid

Y no reaction when heated in steam

no reaction when boiled with acid

Z reacts when heated in steam reacts when warmed with acid

What is the order of reactivity of these three metals?

most reactive → least reactiveA X Z YB X Y ZC Z X YD Y Z X

35 What is the purpose of limestone being used in the blast furnace extraction of iron?

A to generate heat for the furnaceB to produce carbon monoxideC to remove impuritiesD to reduce iron ore

36 Th e transition metals have distinctive properties of their own. Th e table below gives information about four elements.Which element is a transition metal?

Colour of element

Electrical conductivity of element

Colour of oxide

A yellow low colourless

B grey high red

C black high colourless

D grey low white

37 Th ere is one property which distinguishes metals from non-metals most clearly. Which of these properties is a property of all metals without exception?

A Th ey conduct electricity.B Th ey have high melting points.C Th ey have low densities.D Th ey have a grey or silver colour.

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38 Th e diagram shows one method for changing a metal oxide into a metal.

metal oxide

hydrogen

excesshydrogenburning

Which oxide can be changed into a metal using this method?

A calcium oxideB sodium oxideC aluminium oxideD copper(II) oxide

39 Metals have extensive use in our lives. Th e use of a particular metal depends on its properties. Which line in the table below correctly links the property of the metal and its use?

Metal Property Use

A mild steel conducts electricity making garden tools

B aluminium resists corrosion making food containers

C aluminium conducts electricity making aeroplanes

D mild steel high density making car bodies

40 What is produced when sodium metal reacts with water?

A oxygen gas and an acid solutionB hydrogen gas and a neutral solutionC hydrogen gas and an alkaline solutionD oxygen gas and an alkaline solution