2024 O Level Pure Chemistry Paper 1 — All Solutions

Two experiments measure the volume of gas produced during the first 30s of a reaction. The method of gas collection is c…

A scientist investigates the products of the reaction between lead(II) oxide and carbon monoxide. Carbon monoxide, like …

A solid mixture contains magnesium sulfate, MgSO₄, and sand. Which sequence allows pure magnesium sulfate crystals to be…

Mixtures W, X, Y and Z need to be separated. W is solid lead(II) chloride and lead(II) nitrate. X is lubricating oil and…

Three samples of colourless compounds, X, Y and Z, are investigated using paper chromatography. The chromatogram obtaine…

Which statement is correct?…

In experiment 1, concentrated HCl(aq) is placed at one end of a tube, and concentrated NH₃(aq) is placed at the other. G…

The symbols of the ions of three elements are ³²₁₆S²⁻, ³⁵₁₇Cl⁻ and ⁴⁰₂₀Ca²⁺. Which statement is correct?…

Magnesium and oxygen react together to produce magnesium oxide. Which diagram shows the transfer of electrons in the for…

Which row shows the number of electrons used in covalent bonding in each molecule?…

Which statements about metals are correct? 1 An alloy is a compound formed between a metal and at least one other elemen…

Boron nitride has the formula BN. It exists in many crystal forms. Cubic boron nitride, c-BN, has the same structure as …

Aqueous iron(III) chloride, FeCl₃, reacts with aqueous sodium ethanedioate, Na₂C₂O₄. A precipitate of iron(III) ethanedi…

10.00g of an alcohol contains twice as much by mass of oxygen as it does hydrogen. The percentage by mass of hydrogen in…

X is a metallic element that forms the oxide XO₂. A 4.29g sample of XO₂ is heated with an excess of carbon monoxide. The…

In the reaction between 23g of ethanol and excess hydrogen bromide, the mass of bromoethane obtained is 27g. C₂H₅OH + HB…

25 cm³ of 1.0 mol/dm³ aqueous sodium sulfate is added to 25 cm³ of 1.0 mol/dm³ aqueous lead(II) nitrate. Which statement…

Four pairs of solutions are listed. 1 NH₄Cl and NaOH. 2 LiCl and AgNO₃. 3 CH₃COOH and KOH. 4 CaCl₂ and Ba(NO₃)₂. Which r…

Which row describes the results of ion tests with a sample of aqueous zinc sulfate?…

The following substances are available in the laboratory to test for various ions and gases: acidified potassium mangana…

Which reactions are redox reactions? 1 NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l). 2 CuSO₄(aq) + Zn(s) → Cu(s) + ZnSO₄(aq). …

Excess aqueous potassium iodide is reacted with acidified potassium manganate(VII). What is the final colour of the reac…

Which half-equations represent the reaction taking place using inert electrodes during the electrolysis of molten calciu…

Three electrolysis experiments are described. 1 the electrolysis of dilute aqueous sodium chloride with graphite electro…

A simple cell is shown. [Diagram: copper electrode and zinc electrode connected via a voltmeter, dipped in an electrolyt…

Four elements labelled Q, R, S and T are shown in part of the Periodic Table. The letters are not their symbols. [Q is i…

Elements X, Y and Z are all metals. Element X floats on water and reacts rapidly, producing effervescence. Element Y als…

Mercury sulfide, HgS, and copper(II) sulfide, CuS, are compounds in ores which can be heated to extract the pure metal. …

Sample X contains 0.050 moles of chlorine gas. Sample Y contains 0.10 moles of carbon tetrachloride, CCl₄. How many chlo…

The equation for the reaction of hydrogen with oxygen is shown: 2H-H + O=O → 2H₂O. A student makes four statements about…

The energy profile diagram for a reversible reaction is shown. [Diagram: forward reaction is exothermic with high activa…

A catalyst provides an alternative pathway for a reaction. Which row for the catalysed reaction is correct?…

A fractionating column is used to separate the fractions in crude oil. Which trends are indicated by the arrow [pointing…

An isomer of butane is shown. [Structure: CH₃-CH(CH₃)-CH₃, i.e. 2-methylpropane.] The isomer undergoes substitution reac…

Compound X reacts with steam to form compound Y. Compound Y reacts with acidified potassium manganate(VII) to form compo…

Ethanol is made by an addition reaction or by the fermentation of glucose. Which reactions require a catalyst to be pres…

Statins are compounds used in some medicines. An example of a statin is shown. [Complex structure with multiple labelled…

The partial structures of two polymers, P and Q, are shown. [Polymer P: backbone with -CH₂-C(CH₃)(C=O-OCH₃)- repeat unit…

Which list shows typical uses of man-made fibres?…

Which equation represents a redox reaction that removes combustion pollutants in a catalytic converter?…