Cambridge & Pearson Edexcel Past Paper Questions
Browse 35,704 questions from Cambridge O-Level & A-Level and Pearson Edexcel IGCSE & IAL exams. Click any question to practice.
The characteristic odour of rum is attributed to the compound 2-ethyl-3-methylbutanoic acid. [Figure 28.1] Which compound will produce 2-ethyl-3-me...
The acarid mite releases lardolure to attract other mites to a host. This chemical can be destroyed by hydrolysis with acid. [Figure 29.1] A simpli...
An element X consists of four isotopes. The mass spectrum of X is shown in the diagram. [Figure 30.1] What is the relative atomic mass of X?
Which physical properties are due to hydrogen bonding between water molecules? 1 Water has a higher boiling point than H2S. 2 Ice floats on water. ...
Which equilibria, in which all species are gaseous, would have equilibrium constants, Kp, with no units? 1 sulfur dioxide and oxygen in equilibrium...
Why does a mixture of hydrogen gas and bromine gas react together faster at a temperature of 500 K than it does at a temperature of 400 K? 1 A high...
A farmer added lime to damp soil, followed by the nitrogenous fertiliser ammonium sulfate. A chemical reaction occurred in the soil. Which substanc...
Which statements about the reaction of solid sodium bromide with concentrated sulfuric acid are correct? 1 Hydrogen bromide is a product of the rea...
Which statements are true for an SN2 reaction? 1 One bond is broken as another bond is formed. 2 The formation of a transition state involves the c...
The chlorine free radical takes part in the destruction of the ozone layer. Which statements about this free radical are correct? 1 It is formed by...
The diagram shows an experiment. [Figure 38.1] Which processes could be demonstrated by using the above apparatus? 1 the oxidation of ethanol (the ...
A compound has a relative molecular mass of 88 and its molecule contains only four carbon atoms. What could this compound be? 1 a saturated non-cyc...
A monomer undergoes addition polymerisation. A 1 mol sample of the monomer is completely polymerised. How many moles of polymer might, theoreticall...
The ability of an atom in a covalent bond to attract electrons to itself is called its electronegativity. The greater the difference between the el...
Which diagram correctly represents the Boltzmann distribution of molecular energies at two temperatures T₁ and T₂, where T₁ = 300K and T₂ = 310K?
The table gives the radii, in pm, of some ions. [1 pm = 10⁻¹²m] ion radii Na⁺ 102 Mg²⁺ 72 Cs⁺ 167 Cl⁻ 181 O²⁻ 140 Caesium chloride, CsCl, has a dif...
Methanol may be prepared by the reaction between carbon monoxide and hydrogen. CO(g) + 2H₂(g) → CH₃OH(g) The relevant average bond energies are giv...
The reaction pathway diagram below illustrates the energies of reactants, products and the transition state of a reaction. [Figure showing reaction...
Flask X contains 5 dm³ of helium at 12 kPa pressure and flask Y contains 10 dm³ of neon at 6 kPa pressure. If the flasks are connected at constant ...
Use of the Data Booklet is relevant to this question. The enthalpy change of formation, ∆H_f, of hydrated calcium ions is the enthalpy change of th...
The following equilibrium is set up in a mixture of concentrated nitric and sulfuric acids. HNO₃ + H₂SO₄ ⇌ H₂NO₃⁺ + HSO₄⁻ Which row correctly descr...
Which molecule or structure does not contain three atoms bonded at an angle between 109° and 110°?
A dimer, X, is stable when solid but a dynamic equilibrium is set up in solution. X(aq) ⇌ 2Y(aq) A solution of X has an initial concentration of 0....
Equimolar quantities of magnesium carbonate and strontium carbonate are separately heated to bring about complete thermal decomposition. The minimu...
In aqueous solution, the acid HIO disproportionates according to the following equation where m, n, p and q are simple whole numbers in their lowes...
Use of the Data Booklet is relevant to this question. Which mass of solid residue can be obtained from the thermal decomposition of 4.10 g of anhyd...
Which statement explains the observation that magnesium hydroxide dissolves in aqueous ammonium chloride, but not in aqueous sodium chloride?
What happens when chlorine is bubbled through aqueous potassium iodide?
Strontium metal can be obtained by the electrolysis of molten strontium bromide, SrBr₂, using the apparatus shown in the diagram. [Figure showing e...
Which statement about bromine is correct?
Concentrated sulfuric acid reacts with both solid sodium chloride at room temperature and with solid sodium iodide at room temperature. Which row c...
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 ...