Cambridge & Pearson Edexcel Past Paper Questions

Benzoic acid, C6H5COOH, is a weak acid. The K₂ of benzoic acid is 6.31 × 10–5 moldm-3 at 298 K. A 1.00dm³ buffer solution is made at 298 K containi...

Some electrode potentials are shown in Table 3.1. Table 3.1 electrode reaction E/V V2+ + 2e-v ...

The structure of the polydentate ligand, EDTA4—, is shown in Fig. 4.1. :0: :0: :O-CCH2 CH2C-O: NCH₂CH₂N :O-CCH CH₂C- :0: :0: Fig. 4.1 The stability...

Some of the ionic compounds of Group 2 elements undergo thermal decomposition. Thermal decomposition of solid anhydrous magnesium ethanedioate, MgC...

Phosphine, :PH3, and carbon monoxide, :CO, are monodentate ligands found in some transition element complexes.

Benzene can be used to make benzoic acid in the two-step process shown in Fig. 7.1. benzene methylbenzene benzoic acid step 1 st...

Lactic acid, CH3CH(OH)COOH, is the only monomer needed to form the polymer polylactic acid, PLA.

State the reactants and conditions for two different types of reactions that both produce diethylamine, CH3CH2NHCH2CH3. reaction one .................

(a) Define Kw mathematically by completing the expression. Kw = (b) Two solutions, V and W, are described. • V is HCl(aq). • W is NaOH(aq). • The c...

Five ligands are listed in Table 6.1.

Capsaicin is found in chilli peppers. [Structure of capsaicin] You should assume the CH3O group is unreactive in the reactions involved in this que...

The concentration of dissolved oxygen in a sample of water can be measured using the following method. Manganese(II) hydroxide, Mn(OH)₂, is oxidise...

Benzenediazonium chloride, C₆H₅N₂Cl, decomposes in water as shown in the following equation. C₆H₅N₂Cl(aq) + H₂O(l) → C₆H₅OH(aq) + N₂(g) + HCl(aq) A...

Thermometric titrations can be used to determine the standard enthalpy change of neutralisation. The maximum temperature reached in a thermometric ...

A student investigates the rate of reaction when zinc reacts with dilute hydrochloric acid, HCl(aq). Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g) The stude...

Benzenediazonium chloride, C6H5N2Cl, decomposes in water as shown in the following equation. C6H5N2Cl(aq) + H2O(l) → C6H5OH(aq) + N2(g) + HCl(aq) A...

Which species contains a different number of electrons from the other three?

Which factor causes helium to have a higher first ionisation energy than hydrogen?

A 0.216g sample of aluminium carbide reacts with an excess of water to produce methane gas. This is the only carbon-containing product formed in th...

A reaction between two gases takes place on the surface of the catalytic converter of a petrol-engined car. In this reaction, four reactant molecul...

An ion contains 1 nitrogen atom and 2 hydrogen atoms. It has an H–N-H bond angle of approximately 105°. Which row is correct?

Why does ICl have a higher boiling point than Br2?

In this question you may assume that nitrogen behaves as an ideal gas. One atmosphere pressure = 101 kPa. Which volume does 1.0 g of nitrogen occup...

Which statement about the properties associated with the different types of bonding involved is correct?

For which reaction is the enthalpy change an enthalpy change of formation?

Two standard enthalpy change of formation values are given. ΔΗ [VCl2] = −452 kJ mol⁻¹ ∆Η [VC13] = −573 kJ mol⁻¹ What is the enthalpy change for the...

Equations for some reactions of hydrogen peroxide are given. 1 2Fe²⁺ + H2O2 + 2H⁺ → 2Fe³⁺ + 2H2O 2 2MnO4⁻ + 5H2O2 + 6H⁺ → 2Mn²⁺ + 8H2O + 5O2 3 2Fe³...

The equation for the reaction of aqueous thiosulfate ions, S2O3²⁻, and aqueous dioxo-vanadium ions, VO2⁺, is shown. 2S2O3²⁻ + XVO2⁺ + yH⁺ → S4O6²⁻ ...

When some solid Ca5(PO4)3OH is added to a beaker of water, an equilibrium is set up. Ca5(PO4)3OH(s) ⇌ 5Ca²⁺(aq) + 3PO4³⁻(aq) + OH⁻(aq) Which compou...

Gaseous hydrogen and gaseous iodine react to form gaseous hydrogen iodide. H2(g) + I2(g) ⇌ 2HI(g) In an experiment, 2.0 mol of hydrogen and 2.0 mol...

Why does the rate of a gaseous reaction increase when the pressure is increased at a constant temperature?

The Boltzmann distribution for a mixture of gases capable of reaction is shown. The two curves represent the mixture of gases at 25°C and at 35°C. ...

Sodium and sulfur are burned separately in oxygen. Each reaction has a distinctive coloured flame. Which row is correct?

X and Y are elements in Period 3 of the Periodic Table. Y has a greater atomic number than X. The stable ion formed by Y has a greater radius than ...

X is a Group 2 element in either Period 3 or Period 5. X(OH)2 is less soluble in water than Ca(OH)2. When X(NO3)2 is heated, it decomposes. Which r...

Which statement comparing magnesium and barium, or their compounds, is correct?

The colours of the silver halides AgCl, AgBr and AgI differ. The solubilities of these halides in aqueous ammonia also differ. Which row is correct?

The name 'chlorate' is used for an anion consisting of chlorine and oxygen only. In a molecule of ICl, the iodine atom has oxidation number x and t...

The diagram shows the structural formula of a hydrocarbon molecule Q. [Figure showing structural formula of molecule Q] How many of the carbon atom...

Compound X is found in cell walls of some bacteria. Its structural formula is shown. compound X CH3(CH2)17CH=CH(CH2)17CH(OH)CH(CH3)CO2H How many st...

Structural isomerism only should be considered when answering this question. How many straight-chain isomers are there with molecular formula C4H8Cl2?

What is true of every nucleophile?

The diagram shows a synthetic route to produce 1-methylcyclohexanol. [Figure showing reaction scheme from methylcyclohexane to product X then to 1-...

X and Y are the reagents required to convert 1-bromopropane into butanoic acid. [Figure showing reaction scheme from 1-bromopropane to an intermedi...

The table shows three sets of reagents and reaction conditions. Which sets of reagents and conditions can be used to produce 2-chloro-2-methylpropa...

The compound 'leaf alcohol' is partly responsible for the smell of new-mown grass. leaf alcohol CH3CH2CH=CHCH2CH2OH What will be formed when ‘leaf ...

Compound X: • does not react with Tollens' reagent • forms a yellow precipitate with alkaline I2(aq) • does not react with sodium. What could be th...

Which compound can undergo nucleophilic addition?

C2H5COOCH3 is reacted with aqueous acid. The products from this reaction are reacted with LiAlH4 to form two molecules Y and Z. What are the identi...

A sample of propanoic acid of mass 3.70 g reacts with an excess of magnesium. A second sample of propanoic acid of mass 3.70 g reacts with an exces...