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.
When organic refuse decomposes in water carboxylic acids are formed. The water becomes acidic and aquatic life is destroyed. Which additives are su...
In a car engine, non-metallic element X forms a pollutant oxide Y. Further oxidation of Y to Z occurs in the atmosphere. In this further oxidation,...
Sulfur dioxide and sulfites are used in food preservation. Why are they used for this purpose? 1 They are reducing agents so retard the oxidation o...
Which reactions are examples of nucleophilic substitution? 1 CH3CH2Br + OH⁻ → CH3CH2OH + Br⁻ 2 CH3I + H2O H⁺ → CH3OH + HI 3 CH3CH2CH2Cl + NH3 → CH3...
Propanoic acid occurs naturally as a result of the bacterial fermentation of milk, and is partly responsible for the flavour of Swiss cheese. [Figu...
Which structural formulae represent 2,2-dimethylpentane? 1 (CH3)2CHCH2CH(CH3)2 2 (CH3)3CCH2CH2CH3 3 CH3CH2CH2C(CH3)3
The diagram shows some laboratory apparatus. [Figure 40 - Laboratory apparatus for distillation] Which preparations could this apparatus be used fo...
Helium, He, is the second element in the Periodic Table. Tritium is the isotope of hydrogen ³H. What is the same in an atom of He and an atom of ³H?
Which diagram correctly shows the bonding in the ammonium ion, NH4+? key • N electron × H electron [Figure 2.1]
Aluminium is the most abundant metal in the Earth's crust. The extraction of aluminium is carried out by the electrolysis of aluminium oxide dissol...
The esterification reaction ethanol + ethanoic acid ⇌ ethyl ethanoate + water is an equilibrium. The forward reaction is exothermic. How can the va...
Ammonia is manufactured on a large scale by the Haber process. In a particular plant, conditions of 400 °C and 250 atm in the presence of an iron c...
The Boltzmann distribution for a gas at constant temperature is shown below. [Figure 6.1] If the temperature of the gas is reduced by 10°C the grap...
Titanium occurs naturally as the mineral rutile, TiO2. One possible method of extraction of titanium is to reduce the rutile by heating with carbon...
In the conversion of compound X into compound Z, it was found that the reaction proceeded by way of compound Y, which could be isolated. The follow...
Tanzanite is used as a gemstone for jewellery. It is a hydrated calcium aluminium silicate mineral with a chemical formula Ca2AlxSiyO12(OH).6½H2O. ...
0.144 g of an aluminium compound X react with an excess of water, to produce a gas. This gas burns completely in O2 to form H2O and 72 cm³ of CO2 o...
Use of the Data Booklet is relevant to this question. Which element is likely to have an electronegativity similar to that of aluminium?
In 1999, researchers working in the USA believed that they had made a new element and that it had the following electronic configuration. [Rn] 5f14...
The highest oxides of the elements sodium to chlorine are separately added to water. Which diagram best represents the pH of the resulting mixtures...
The diagram shows the first ionisation energies of 11 consecutive elements. [Figure 15.1] Which type of elements are labelled X and Y?
Why does aluminium oxide dissolve in sodium hydroxide solution?
Concentrated sulfuric acid can behave both as a strong acid and as an oxidising agent. With which compound does concentrated sulfuric acid react in...
In the Contact process, what is the nature of the gaseous product and what is the identity of the catalyst?
Which reagent gives the same visible result with propanal and with propan-2-ol?
Which halogenoalkane will undergo an SN1 reaction and produce a yellow precipitate when AgNO3(aq) is added to it?
Which reaction will give 2-chloropropane in the best yield?
The products obtained by cracking an alkane, X, are methane, ethene and propene. The mole fraction of ethene in the products is 0.5. What is the id...
Which compound does not show cis-trans isomerism?
Which formulae show propanone and propanal as different compounds?
How many isomers with the formula C5H10 have structures that involve π bonding?
1,1-dichloropropane reacts with aqueous sodium hydroxide in a series of steps to give propanal. CH3CH2CHCl2 --NaOH(aq)--> CH3CH2CHO Which term desc...
The ester CH3CH2CH2CO2CH3 is responsible for the aroma of apples. When this ester is hydrolysed by acid in the stomach, what is the empirical formu...
This question should be answered by considering the reactions of KMnO4 with different functional groups under the stated conditions. The diagram sh...
Which reaction would not give ethanoic acid as a product?
Solid calcium carbonate is added to 100 cm³ of dilute hydrochloric acid and the rate of the reaction is measured. 100 cm³ of distilled water is the...
Which equations apply to an ideal gas? [p = pressure, V = volume, M = molar mass, ρ = density, c = concentration, R = gas constant, T = temperature...
What is involved when a hydrogen bond is formed between two molecules? 1 a hydrogen atom bonded to an atom less electronegative than itself 2 a lon...
When the yellow liquid NCl3 is stirred into aqueous sodium hydroxide, the reaction that occurs can be represented by the following equation. 2NCl3(...
In a car engine pollutant oxide Y, which contains non-metallic element X, is formed. Further oxidation of Y to Z occurs in the atmosphere. In this ...
Which compounds can be obtained from ethene in a single reaction? 1 CH3CH3 2 CH2CH2 3 HOCH2CH2OH
Which compounds when heated under reflux with an excess of hot acidified potassium dichromate(VI), give a product with a chiral centre? 1 CH3CH2CCH...
In the reaction between an aldehyde and HCN, catalysed by NaCN, which statements about the reaction mechanism are correct? 1 A new carbon-carbon bo...
An organic compound, X, will react with an excess of calcium metal to produce a salt with the empirical formula CaC4H6O4. What could be the identit...
The molecular energy distribution curve represents the variation in energy of the molecules of a gas at room temperature. [Figure 1.1] Which curve ...
In which species are the numbers of protons, neutrons and electrons all different?
What is the most likely shape of a molecule of hydrazine, N2H4?
In which species does the underlined atom have an incomplete outer shell?
Which solid contains more than one kind of bonding?
Use of the Data Booklet is relevant to this question. The gas laws can be summarised in the ideal gas equation. pV = nRT 0.96 g of oxygen gas is co...