Cambridge Past Paper Questions

Chlorine atoms in the upper atmosphere cause the breakdown of ozone. Cl + O₃ → O₂ + ClO ClO + O → Cl + O₂ Which statements are correct when referri...

An unknown organic compound Z reacts with sodium to give a combustible gas as one product. Z does not give a yellow precipitate with alkaline aqueo...

Compound X has the molecular formula C₃H₆O₃. Heating X under reflux with acidified K₂Cr₂O₇ forms HO₂CCOCO₂H. Reacting X with NaBH₄ forms HOCH₂CH(OH...

Which ion has the same electronic configuration as Cl¯?

Compounds J and K each contain 40% carbon by mass. What could J and K be?

Two moles of compound P were placed in a sealed container. The container was heated and P was partially decomposed to produce Q and R only. A dynam...

The boiling points of methane, ethane, propane and butane are given. compound CH4 boiling point/K 112 compound CH3CH3 boiling point/K 185 compound ...

The characteristic smell of garlic is due to alliin. [Figure showing the structure of alliin with bond angles x, y and z marked]. What are the appr...

Which gas sample contains the fewest molecules?

A student mixed 25.0 cm³ of 4.00 mol dm⁻³ hydrochloric acid with an equal volume of 4.00 mol dm⁻³ sodium hydroxide. The initial temperature of both...

HOCl(aq) is the molecule that kills bacteria when chlorine is added to water. The following reaction produces this molecule. Cl₂(g) + H₂O(l) ⇌ HOCl...

All the reactants and products of an exothermic reaction are gaseous. Which statement about this reaction is correct?

Oxidation of ethanedioate ions by acidified manganate(VII) ions is very slow at room temperature. 2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ → 2Mn²⁺ + 10CO₂ + 8H₂O Mn...

Ammonia is manufactured from nitrogen and hydrogen using the Haber process. N₂(g) + 3H₂(g) ⇌ 2NH₃(g) What is the expression for K for this equilibr...

The electrical conductivities of two compounds, Y and Z, are shown in the table. conductivity of the compound in the liquid state conductivity of t...

Which reagent, when mixed with ammonium sulfate and then heated, liberates ammonia?

Why does barium react more rapidly with cold water than magnesium does?

The magnitude of property X of five elements from the third period of the Periodic Table, P, Q, R, S and T is shown. P, Q, R, S and T have consecut...

Some uses of chlorine and bromine are given. Which is a use of bromine?

In an experiment, 0.600 mol of chlorine gas, Cl₂, is reacted with an excess of hot aqueous sodium hydroxide. One of the products is NaClO₃. Which m...

Z is an anhydrous compound of a Group 2 element. When it is heated, Z undergoes thermal decomposition to produce two different gases. Z has relativ...

Methylamine, CH₃NH₂, has very similar chemical properties to ammonia, NH₃. Methylamine reacts with hydrogen chloride to form a white crystalline sa...

Structural isomerism and stereoisomerism should be considered when answering this question. How many isomers with the formula C₄H₈ have structures ...

Kerosene is used as an aircraft fuel. Q is one of the molecules in kerosene and has the skeletal formula shown. [Figure showing skeletal formula of...

Which radical is most likely to form by the homolytic fission of one covalent bond in bromochloromethane, CH₂BrCl?

Propene undergoes a variety of reactions. Which row is correct?

Polymerisation of ethene gives poly(ethene). How does the bonding between carbon atoms in poly(ethene) compare with that in ethene?

Diols in which both hydroxy groups are bonded to the same carbon can spontaneously eliminate a molecule of water to produce a carbonyl compound. Wh...

Propan-2-ol undergoes many reactions. Which row is correct?

Ethane-1,2-diol has the following structure. [Figure showing HO-CH₂-CH₂-OH]. Without breaking the C-C bond, there are five possible oxidation produ...

CH₃CH₂COCH₂CH₃ reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct?

Compound X, CH₃CH(OH)CH(CHO)CH₃, is heated under reflux with an excess of acidified K₂Cr₂O₇ to form compound Y. Both X and Y are separately warmed ...

Which two compounds can react together to produce an ester?

Nitrogen and phosphorus are both in Group 15 of the Periodic Table. Phosphorus forms a chloride with the formula PCl₅ but nitrogen does not form NC...

When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its volume changes from 76.0 cm³ to 20.5 cm³. Which stateme...

Which of these statements are always correct? 1 The sum of the oxidation numbers of all the atoms in a compound is zero. 2 The oxidation number of ...

Sulfur dioxide and oxygen react in the gas phase. 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) ∆H = –197 kJ mol⁻¹ Which statements are correct? 1 Increasing the press...

Three test-tubes, X, Y, and Z, each contain a small amount of water. • A small amount of NaCl is added to test-tube X. • A small amount of SiCl₄ is...

Sodium chloride and sodium iodide react with concentrated sulfuric acid. Which statements are correct? 1 Sodium chloride is not oxidised by concent...

Which compounds can be obtained from but-2-ene in a single reaction? 1 CH₃CH(OH)CH(OH)CH₃ 2 CH₃CH(OH)CH₂CH₃ 3 CH₃CO₂H

Which statements help to explain the mechanism of the reaction between 1-chloropropane and ammonia? 1 1-chloropropane has a δ− chlorine atom that f...

Which compounds react with alkaline aqueous iodine to give a pale yellow precipitate of tri-iodomethane? 1 butanone 2 ethanal 3 propan-2-ol

Propanoic acid occurs naturally as a result of the bacterial fermentation of milk and is partly responsible for the flavour of Swiss cheese. [Figur...

(a) The table shows information about some of the elements in the third period. element | Na | Mg | Al | P | S | Cl ---|---|---|---|---|---|--- at...

Hydrogen halides are compounds formed when halogens (Group 17 elements) react with hydrogen. The bond polarity of the hydrogen halides decreases fr...

(a) A series of reactions starting from 1-bromobutane is shown. [Figure showing reaction scheme: 1-bromobutane reacts with HCN and KCN to form P, t...

The concentration of hydrogen peroxide may be given in moldm-³ or as 'volume strength'. You will determine the concentration of hydrogen peroxide i...

You will carry out a second experiment to determine the concentration of hydrogen peroxide, FA 1, in moldm⁻³, by titration with acidified aqueous p...

Qualitative Analysis At each stage of any test you are to record details of the following. • colour changes seen • the formation of any precipitate...

The mass spectrum of silicon is shown. [Diagram: A mass spectrum showing relative intensity on the y-axis (up to 1.0) and m/e on the x-axis (from 2...