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.
Two moles of compound P were placed in a vessel. The vessel was heated and compound P was partly decomposed to produce Q and R. A dynamic equilibri...
The value of the third ionisation energy of aluminium is 2740 kJ mol⁻¹. Which correctly represents this statement?
Methanol is manufactured by reacting carbon dioxide and hydrogen. CO2(g) + 3H2(g) ⇌ CH3OH(g) + H2O(g) ∆H = −49 kJ mol⁻¹ What would increase the equ...
Which molecule has the largest overall dipole?
In which substance does nitrogen exhibit the highest oxidation state?
Red lead oxide, Pb3O4, is used in metal priming paints. It can be made by heating PbO in air. 6PbO(s) + O2(g) → 2Pb3O4(s) Which two values are need...
Which gas is present in the exhaust fumes of a car engine in a much greater amount than any other gas?
Slaked lime, Ca(OH)2, may be made from limestone, CaCO3. On heating in a lime kiln at 1000°C, limestone decomposes as follows. reaction 1 CaCO3(s) ...
The period 4 elements gallium (Ga), germanium (Ge), arsenic (As) and selenium (Se) are the elements below aluminium, silicon, phosphorus and sulfur...
Chlorine shows oxidation states ranging from −1 to +7 in its compounds. What are the reagent(s) and conditions necessary for the oxidation of eleme...
What can be seen when a piece of magnesium ribbon is placed in cold water?
Use of the Data Booklet is relevant to this question. Sodium and sulfur react together to form sodium sulfide, Na2S. How do the atomic radius and i...
Which substance does not produce a poisonous gas, when burnt in a limited amount of air?
Use of the Data Booklet is relevant to this question. A sample of propyl ethanoate is hydrolysed by heating under reflux with aqueous sodium hydrox...
Which diagram gives the skeletal formula of 2-chloropentan-3-ol?
When 1-bromopropane is treated in succession with two reagents, X and Y, it produces propanoic acid. What are reagents X and Y?
Isomers X and Y both react with HBr. [Figure 23.1] A mixture of X and Y is reacted with HBr. Which three structures represent three different possi...
Oct-1-ene, CH3(CH2)5CH=CH2, is subjected to thermal cracking. Which combination of compounds W, X, Y and Z can be obtained? CH2=CH2 W CH3CH=CH2 X C...
When phenacyl chloride, C6H5COCH2Cl, is reacted with aqueous NaOH, the substitution reaction follows an SN2 mechanism. Which structure represents a...
Complete combustion of compound X gives carbon dioxide and water only. A sample of X is mixed with aqueous potassium(V) dichromate and boiled under...
A compound Y has the following properties. • It is a liquid at room temperature and atmospheric pressure. • It does not mix completely with water. ...
Coniine is the major constituent of the poison 'oil of hemlock'. [Figure 28.1] Coniine can be synthesised by reacting ammonia with a dibromo compou...
A common industrial solvent is a mixture of propanone, CH3COCH3, and pentyl ethanoate CH3CO2(CH2)4CH3. Which reagent would have no reaction with th...
An organic compound will decolorise dilute acidified aqueous potassium manganate(VII) on warming, but will not decolorise bromine water. What could...
Which of the following molecules and ions have a regular trigonal planar shape?
Ammonia and chlorine react in the gas phase. 8NH3 + 3Cl2 → N2 + 6NH4Cl Which statements are correct?
Concentrated sulfuric acid behaves as a strong acid when it reacts with water. H2SO4(l) + aq → H+(aq) + HSO4⁻(aq) The HSO4⁻ ion formed behaves as a...
Silver chloride dissolves in aqueous ammonia. What happens in this process?
Compared with the HCl molecule, the bond .....X..... of the HBr molecule is .....Y...... Which pairs of words correctly complete the above sentence?
Which statements are true about the Haber process for the manufacture of ammonia?
Which compounds can be obtained from propene in a single reaction?
What are the same for a pair of optical isomers?
Which statements about the photochemical chlorination of ethane are correct?
The compound shown is a hormone produced during pregnancy to suppress ovulation. [Figure 40.1] Which reagents would give positive results with this...
During the electrolysis of molten aluminium oxide to produce aluminium, using carbon electrodes, two consecutive reactions occur at the anode, each...
Equations involving four enthalpy changes are shown. Na(g) → Na⁺(g) + e⁻ ΔΗ = W Na(g) → Na²⁺(g) + 2e⁻ ΔΗ = X Na(s) → Na(g) ΔΗ = Y Na(s) → Na²⁺(g) +...
Which ion has more electrons than protons and more protons than neutrons? [H = ¹H ; D = ²H ; O = ¹⁶O]
Which factor can affect the value of the activation energy of a reaction?
The diagram shows the Maxwell-Boltzmann energy distribution curves for molecules of a sample of a gas at two different temperatures. Which letter o...
Which pair of elements has chemical bonds of the same type between their atoms in the solid state?
Ethanol has a boiling point of 78°C. At 101 kPa and 79°C ethanol vapour does not perfectly obey the gas equation pV = nRT. What is the reason for t...
The reaction between sulfur dioxide and oxygen is a dynamic equilibrium. 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) What happens when the pressure of the system is ...
Dicarbon monoxide, C₂O, is found in dust clouds in space. Analysis of it shows that the sequence of atoms in this molecule is C–C–O. All bonds are ...
Use of the Data Booklet is relevant to this question. A student mixed 25 cm³ of 0.10 moldm⁻³ sodium hydroxide solution with 25 cm³ of 0.10 moldm⁻³ ...
Which energy change corresponds to the enthalpy change of atomisation of hydrogen at 298 K?
Propanone has molecular formula C₃H₆O. The enthalpy change of combustion of hydrogen is –286 kJ mol⁻¹. The enthalpy change of combustion of carbon ...
Use of the Data Booklet is relevant to this question. Magnesium nitrate, Mg(NO₃)₂, will decompose when heated to give a white solid and a mixture o...
In which row of the table are all statements comparing the compounds of calcium and barium correct? [Figure 14.1]
Many modern cars are fitted with halogen lamps. When such lamps are first switched on, a distinct purple colour can be seen. Which species is respo...
The trends in three physical properties of the elements Na, Mg, Al, Si, P and S are shown in the graphs. [Figure 16.1] Which physical property is n...