Cambridge Past Paper Questions

Nine compounds have molecular formula C₄H₈Br₂. Which compound may be synthesised from an alkene by an addition reaction?

When ethanal, CH₃CHO, reacts with HCN and the organic product is hydrolysed by aqueous acid, organic compound Y is formed. When propanal, C₂H₅CHO, ...

Which sequence of reagents may be used in the laboratory to convert propan-1-ol into 2-bromopropane?

Esters are frequently used as solvents and as flavouring agents in fruit drinks and confectionery. An ester C₈H₁₂Br₂O₄ can be prepared in low yield...

Many, but not all, organic reactions need to be heated before reaction occurs. Which reaction occurs at a good rate at room temperature (20 °C)?

Which pair of reagents will take part in a redox reaction?

Part of the structure of strobilurin, a fungicide, is shown. R and R' are inert groups. [Figure showing part of strobilurin structure] If strobilur...

Fluoroalkenes are used to make polymers such as poly(vinyl)fluoride (PVF). PVF is used to make non-flammable interiors for aircraft. The diagram sh...

CH₃CH₂COCH₂CH₃ reacts with hydrogen cyanide to form a cyanohydrin. Which feature applies to the product?

Which of the compounds shown have chiral carbon atoms? [Figure showing four organic compounds (1, 2, 3, 4)]

When ammonia, NH₃, is produced in a school or college laboratory, it is usually dried before being collected. Which drying agents may be used to dr...

Zirconium, Zr, proton number 40, is a metal which is used in corrosion-resistant alloys. Zirconium metal is extracted from the oxide ZrO₂ by the fo...

Which statements about covalent bonds are correct? 1 A triple bond consists of one π bond and two σ bonds. 2 The electron density in a σ bond is hi...

A student puts 10 cm³ of 0.100 mol dm⁻³ sulfuric acid into one test-tube and 10 cm³ of 0.100 mol dm⁻³ ethanoic acid into another test-tube. He then...

In which ways are the main reactions in the Haber and Contact processes similar? 1 A higher yield is favoured by higher pressures. 2 The reaction i...

A car burning lead-free fuel has a catalytic converter fitted to its exhaust. On analysis its exhaust gases are shown to contain small quantities o...

The diagram shows a compound present in smoke from burning garden waste. [Figure showing C3H4O structure] Which reagents would undergo a colour cha...

Organic acids and alcohols react together to form esters. Which pairs of compounds could produce a product of molecular formula C₄H₆O₄? 1 CH₃CO₂H a...

Use of the Data Booklet is relevant for this question. In an organic synthesis, a 62% yield of product is achieved. Which of these conversions are ...

A reaction pathway diagram is shown. [Figure showing reaction pathway diagram with two humps] Which reactions would have such a profile? 1 (CH₃)₃CB...

In the Haber process for the manufacture of ammonia, why is the heterogeneous catalyst iron in a finely divided state?

The following equations the letters W, X, Y and Z all represent whole numbers. When correctly balanced, which equation requires one of letters W, X...

Use of the Data Booklet is relevant to this question. From which particle is the removal of an electron the most difficult?

Use of the Data Booklet is relevant to this question. 560 kg of nitrogen and 120 kg of hydrogen are pressurised, heated and passed over an iron cat...

The presence of dipoles helps to explain why the element Br2 and the compound CHCl3 exist as liquids at room temperature. Which types of dipole are...

Three compounds have the physical properties shown in the table. [Figure for table of properties of P, Q, R] What might be the identities of P, Q a...

For the equilibrium 2SO2(g) + O2(g) ⇌ 2SO3(g), what will change the value of Kp?

Which pollutant, present in the exhaust fumes of an internal combustion engine, has an element in the +2 oxidation state and an odd number of elect...

The use of sucrose in food processing depends in part on osmotic pressure, symbol Π. In dilute solution, Π varies with concentration in a similar w...

Hess’s Law can be used to calculate the average C–H bond energy in methane. ΔH°at = standard enthalpy change of atomisation ΔH°f = standard enthalp...

The amount of titanium dioxide in an ore can be determined by using the following reaction. 3TiO2 + 4BrF3 → 3TiF4 + 2Br2 + 3O2 Which element increa...

For the reaction W(aq) + 2X(aq) ⇌ 2Y(aq) + 3Z(aq) what are the correct units for the equilibrium constant Kc?

Methyl mercaptan, CH3SH, has a foul smell and is often used to impart a smell to natural gas. What will be formed when CH3SH is burned in an excess...

Nitrogenous fertilisers are used extensively in modern farming. If rainwater washes excess fertiliser into a nearby lake, a process called eutrophi...

Chlorine can be manufactured from brine in a diaphragm cell. Which row represents the correct electrodes?

Sodium iodide reacts with concentrated sulfuric acid. The equation which represents one of the reactions that takes place is shown. 8NaI + 9H2SO4 →...

The standard enthalpy changes of formation of HCl and HI are –92 kJ mol⁻¹ and +26 kJ mol⁻¹ respectively. Which statement is most important in expla...

Lime mortar is made from quicklime, water and sand. Over a period of time, lime mortar changes into a much harder form. Both fresh and old lime mor...

Ar, Ca²⁺ and K⁺, contain the same number of electrons. In which order do their radii increase?

Bromine and propene undergo an addition reaction. Which is a property of the product?

Buta-1,3-diene is currently obtained from fossil fuel sources. In future it may be obtained from ethanol, which can be produced from non-food agric...

Use of the Data Booklet is relevant to this question. Which bond in the structure below has the lowest bond energy? [Figure for molecule structure]

Ethanal, CH3CHO, can be reduced using NaBH4 in aqueous ethanol. This is a nucleophilic addition reaction. What could be the first step of this mech...

In a sequence of reactions, ethanal is converted into a compound H. [Figure for reaction scheme] What could H be?

What is involved in the mechanism of the reaction between aqueous sodium hydroxide and 2-bromo-2-methylbutane?

Use of the Data Booklet is relevant to this question. 2.30 g of ethanol were mixed with aqueous acidified potassium dichromate(VI). The desired pro...

The molecule shown is optically active. [Figure for molecule structure] How many chiral carbon atoms are present in this molecule?

Which reagent could best be used to distinguish between cyclohexene and cyclohexanol?

Compound X, molecular formula C4H8, undergoes the following reactions. [Figure for reaction scheme] What is the formula of compound Z?

How many of the isomeric alcohols with the formula C4H9OH will produce an alkene that has cis and trans isomers, on treatment with conc. H2SO4?