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.
CH3(CH2)5CHBrCH3 exists as a pair of stereoisomers.
Compound W has molecular formula C4H10O. It contains only one functional group.
Explain the lack of reactivity of nitrogen gas, N2(g).
N2(g) reacts with H2(g) in the Haber process, as shown in reaction 1. reaction 1 N2(g) + 3H2(g) ⇌ 2NH3(g) ∆H = -x kJ mol-1 Table 2.1 shows the diff...
Write an equation to show the reaction for the standard enthalpy change of formation of H2O. Include state symbols.
NH3(g) reacts with HCl(g) to produce NH4Cl(s), as shown. NH3(g) + HCl(g) → NH4Cl(s)
M reacts to form R by the addition of one reagent, as shown in Fig. 5.1. [Figure 5.1] Identify the reagent and conditions for this reaction.
Sodium sulfite is oxidised when it reacts with excess iodine. Na2SO3(aq) + I2(aq) + H2O(l) → Na2SO4(aq) + 2HI(aq) The remaining iodine is then titr...
2 Iodate ions contain iodine and oxygen. They have the formula IOx⁻ where x is an integer. In this experiment you will determine the value of x in ...
3 FB 7 is an aqueous solution of a salt containing one cation and one anion, both of which are listed in the Qualitative analysis notes.
2 A sample of ammonium bromide has been accidentally mixed with another salt. A student suggests that the percentage purity of the ammonium bromide...
Describe the trend in the solubility of the hydroxides of magnesium, calcium and strontium. Explain your answer. most soluble > least soluble
Define transition element.
When a sample of hydrated lithium ethanedioate, Li₂C₂O₄•H₂O, is gently heated, two gaseous products are formed and a white solid residue remains. T...
Define standard electrode potential, E°, including a description of standard conditions.
In aqueous solution, persulfate ions, S₂O₈²⁻, react with iodide ions, as shown in reaction 1. reaction 1 S₂O₈²⁻ + 2I⁻ → 2SO₄²⁻ + I₂ The rate of rea...
State what is meant by partition coefficient, Kpc.
Four esters, A, B, C and D, with the molecular formula C₆H₁₂O₂ are shown in Fig. 7.1. [Figure 7.1]
Neotame is an artificial sweetener added to some foods. [Figure 8.1]
Samples of phenol, C₆H₅OH, are reacted separately with sodium and with dilute nitric acid. [Figure 9.1]
Describe the trend in the solubility of the sulfates of magnesium, calcium and strontium. Explain your answer. most soluble > > least soluble
Lithium nitrate, LiNO₃, decomposes on heating in a similar way to Group 2 nitrates to give the metal oxide, a brown gas and oxygen. Write an equati...
Carbon disulfide, CS₂, is flammable and reacts readily with oxygen, as shown in reaction 1. reaction 1 CS₂(g) + 3O₂(g) → CO₂(g) + 2SO₂(g) Table 3.1...
Nitrosyl chloride, NOCl, can be formed by the reaction between nitrogen monoxide and chlorine, as shown. 2NO + Cl₂ → 2NOCl The initial rate of this...
Aqueous solutions of methanoic acid, HCOOH, and propanoic acid, CH₃CH₂COOH, are mixed together. An equilibrium is set up between two conjugate acid...
Methyl red can be synthesised as shown in Fig. 7.1. [Figure 7.1 showing the reaction scheme starting from compound P (2-nitrobenzoic acid), going t...
State the relative basicities of phenylamine, C₆H₅NH₂, benzylamine, C₆H₅CH₂NH₂, and ammonia, NH₃, in aqueous solution. Explain your answer. most ba...
Explain why trichloroethanoic acid, CCl₃COOH, is more acidic than ethanoic acid, CH₃COOH.
When a sample of hydrated lithium ethanedioate, Li2C2O4•H2O, is gently heated, two gaseous products are formed and a white solid residue remains. T...
Define standard electrode potential, Eº, including a description of standard conditions.
In aqueous solution, persulfate ions, S2O82-, react with iodide ions, as shown in reaction 1. reaction 1 S2O82- + 2I-→2SO42- + I2 The rate of react...
Four esters, A, B, C and D, with the molecular formula C6H12O2 are shown in Fig. 7.1. [Figure 7.1]
Samples of phenol, C6H5OH, are reacted separately with sodium and with dilute nitric acid. [Figure 9.1] Write the equation for the reaction of C6H5...
Titration can be used to determine the concentration of dissolved oxygen in samples of river water. The procedure for the experiment is given. step...
The activation energy, EA, for the reaction between dilute hydrochloric acid, HCl(aq), and aqueous sodium thiosulfate, Na₂S₂O₃(aq), can be determin...
Calcium carbonate, CaCO3(s), decomposes when heated, as shown. CaCO3(s) → CaO(s) + CO2(g) The enthalpy change of reaction, ∆Η, for the thermal deco...
This question is about an experiment to investigate the effect of temperature on the equilibrium constant, K₁, of the reaction shown. Fe³⁺(aq) + SC...
Consider the following statements. 1 Silicon dioxide has a higher melting point than sulfur dioxide. 2 Ammonia has a higher boiling point than pho...
How many neutrons are contained in an atom of iron with a mass number of 60?
The diagram shows a Boltzmann distribution of molecular energies for a gaseous reaction at two different temperatures and two different activation ...
The reaction between sulfur dioxide and oxygen has the equation shown. 2SO2(g) + O2(g) ⇌ 2SO3(g) ΔH = –197 kJ mol⁻¹ 1.0 mol of SO2 and 1.0 mol of...
'Red lead' is a red pigment with the formula Pb3O4. Every formula unit of 'red lead' is the same. Each formula unit contains three lead ions and f...
Some standard enthalpy of combustion data are given. [Table with substance (C(s), H2(g), CH3OH(l)) and standard enthalpy change of combustion/kJ m...
In the Haber process, the reaction between the two gaseous reactants requires the use of a catalyst that contains a transition element. What is th...
Aqueous hydrogen peroxide, H2O2, decomposes into water and oxygen in the presence of a suitable catalyst. 50 cm³ of a 0.50 mol dm⁻³ solution of hy...
The average intermolecular forces in water are much stronger than the average intermolecular forces in steam. The average intermolecular forces in...
An experiment is carried out to determine the value of x in hydrated lithium hydroxide, LiOH•xH2O. A sample of the solid is heated in a crucible ov...
A sample of an ideal gas occupies 240 cm³ at 37 °C and 100 kPa. How many moles of gas are present in the sample?
Under certain conditions, CCl4 and H2O react as shown. The activation energy for the reaction is +62 kJ mol⁻¹. CCl4 + 2H2O → CO2 + 4HCl ΔH = −61.5...
A helium ion contains two protons, two neutrons and one electron. This helium ion and a proton are passed separately through a uniform electric fi...