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2019 O Level Pure Chemistry Paper 1 — All Solutions

40 multiple-choice questions · Free video solutions

Gas Preparation / Drying and Collecting Gases

A gas turns moist red litmus paper blue, is soluble in water and is less dense than air. Which diagram shows a correct w…

Qualitative Analysis / Test for Sulfate Ions

In addition to sodium ions and chloride ions, sea water contains calcium ions and sulfate ions. Which method could be us…

Separation Techniques / Distillation and Separating Funnel

Liquids X and Y are immiscible. • X has a higher boiling point than Y. • X has a higher density than Y. • X and Y can be…

Qualitative Analysis / Observations and Colour Changes

Three different experiments with colour changes are carried out. 1 Sulfur dioxide is tested with acidified potassium man…

Atomic Structure / Isotopes and Ions

An isotope of element Q can be written as ³²₁₆Q. Particle R has four more neutrons, one more proton and one more electro…

Structure and Bonding / Diamond and Graphite

Which property is common to both diamond and graphite?…

Ionic Bonding / Properties of Ionic Compounds

Both calcium chloride and potassium chloride are ionic compounds. Which statements about these compounds are correct? 1 …

Macromolecules / Substances and Bonding

Statements about two substances X and Y are given. X is a gas at room temperature and pressure that burns to produce car…

Metallic Bonding

For which does 1 mole of the metal have the most electrons in its 'sea of electrons'?…

Stoichiometry / Mole Calculations

A carbohydrate has the formula (CH₂O)₆. One mole of this carbohydrate is burned in excess oxygen and the gas formed is c…

Stoichiometry / Reacting Masses and Limiting Reagent

Magnesium reacts with dilute sulfuric acid to form magnesium sulfate and hydrogen. Mg + H₂SO₄ → MgSO₄ + H₂ 2.4 g of magn…

Stoichiometry / Relative Atomic Mass

4.00 g of a metal oxide, XO₂, is reduced to form 3.15 g of metal X. What is the identity of X?…

Electrolysis / Products of Electrolysis

Four different conditions under which sodium chloride is electrolysed using inert electrodes are listed. 1 concentrated …

Electrolysis / Electrolysis of Copper(II) Sulfate

Aqueous copper(II) sulfate is electrolysed using a positive carbon electrode and a negative copper electrode. Which row …

Energetics / Energy Profiles and Activation Energy

The energy profile diagram for the reversible reaction 2NH₃ ⇌ N₂ + 3H₂ is shown. Which statements about this reaction ar…

Energetics / Enthalpy of Combustion

The table shows information about some fuels. Which statements are correct? 1 Octane produces more heat than hydrogen or…

Rate of Reaction / Effect of Concentration

Dilute hydrochloric acid is reacted with 1.2 g of magnesium ribbon at room temperature in two experiments, experiment 1 …

Rate of Reaction / Catalysts and Temperature

How is the activation energy for a reaction between two gases changed when it is carried out either in the presence of a…

Redox / Oxidation and Reduction

In which reaction is substance X reduced?…

Acids and Bases / pH and Neutralisation

An aqueous solution of sodium hydroxide has a pH of 10. Which compounds could be added to the aqueous sodium hydroxide t…

Qualitative Analysis / Identifying Ions

Y is a white solid mixture that has the following properties. Y dissolves in water. When dilute hydrochloric acid is add…

Qualitative Analysis / Tests for Gases

The diagram shows two substances, R and S, being heated together. Which row is correct?…

Air and the Atmosphere / Composition of Air

The oxygen in air can be removed by passing over heated copper using the apparatus in the diagram. 50 cm³ of air is coll…

Periodic Table / Metals and Non-metals

Element Z forms a positive ion when it reacts with oxygen. Which statement about Z is correct?…

Group I / Reactions of Lithium

Lithium reacts with water to form solution P and gas Q. When solution P reacts with dilute sulfuric acid, salt R is form…

Transition Elements / Properties

Vanadium has various oxidation states and forms coloured compounds. The aqueous VO²⁺ ion is blue while the aqueous VO₂⁺ …

Periodic Table / Properties of Elements

Five statements about different elements are given. 1 proton number = 24 2 cuts easily with a knife 3 constituent of bra…

Metals / Reactivity Series

Some of the reactions of three metals, W, X and Y, or compounds of these metals, are described. The oxide of W is reduce…

Metals / Extraction of Metals

Metal M can be obtained from its oxide by heating with carbon and from its aqueous chloride by electrolysis. Which metal…

Metals / Iron and Recycling

Which statements about iron are correct? 1 Iron is extracted from its ore by heating with carbon. 2 Iron is the main com…

Air and the Atmosphere / Acid Rain

Which pair of gases are involved in the formation of acid rain?…

Petroleum / Fractional Distillation

Petroleum can be separated into fractions using fractional distillation. Which statements are correct? 1 Alkanes used in…

Organic Chemistry / Isomerism

Which diagrams represent the two isomers of butane, C₄H₁₀?…

Organic Chemistry / Cracking

The equation for the cracking of an alkane is shown. C₁₀H₂₂ → C₄H₁₀ + X + Y Compound X has two carbon atoms. X decolouri…

Organic Chemistry / Hydrogenation of Oils

What is added to polyunsaturated vegetable oils to form solid margarine?…

Organic Chemistry / Alkenes and Isomers

Two of the isomers of butene, C₄H₈, are shown. CH₂=CHCH₂CH₃ and CH₃CH=CHCH₃ How many of the statements about these two i…

Organic Chemistry / Uses of Ethanol

Which statements about ethanol are correct? Ethanol can be used: 1 as the source of energy in car engines 2 to dissolve …

Organic Chemistry / Carboxylic Acids

Which bond in a molecule of ethanoic acid is broken when it reacts with magnesium?…

Organic Chemistry / Esters

Which alcohol and acid can be reacted together to make the ester CH₃CH₂CH₂CO₂CH₃?…

Polymers / Addition and Condensation Polymerisation

The diagram shows the partial structure of a polymer. Which statement about this polymer is correct?…