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.
Nickel forms complexes. Give the formula and charge of the tetrahedral complex formed by Ni atoms with carbon monoxide molecules. Carbon monoxide i...
P, Q, R, S, T, U, and V are the seven structural isomers with molecular formula C5H10O that have a carbonyl group. P CH3(CH2)3CHO S (CH3)3CCHO V (C...
Asparagine and aspartic acid are two naturally occurring amino acids. Their structures and isoelectric points are shown in Table 8.1. Table 8.1 ami...
Compound X is made from benzene by the route shown in Fig. 9.1. [Figure 9.1]
(a) Solutions of Group 2 hydrogencarbonates, M(HCO3)2, decompose on heating to give the corresponding metal carbonate, carbon dioxide and water. (i...
(a) Iron can form stable ions in the +2 and +3 oxidation states. Explain why transition elements have variable oxidation states. [1] (b) Aqueous s...
(a) Solid manganese(IV) oxide, MnO2, catalyses the decomposition of hydrogen peroxide. 2H2O2(aq) → 2H2O(l) + O2(g) State the type of catalysis for ...
(a) Define standard cell potential, Ecell. Include a description of standard conditions. [2] (b) The Daniell cell is an electrochemical cell consi...
(a) Copper shows typical properties of transition elements, including its behaviour as a catalyst. Complete Table 5.1 to show the total number of u...
(a) Thin-layer and gas/liquid chromatography can be used to separate mixtures into their individual components. (i) Define the following terms used...
(a) State the relative acidities of bromoethanoic acid, BrCH2COOH, chloroethanoic acid, CICH2COOH, ethanoic acid, CH3COOH and ethanol, CH3CH2OH. Ex...
(a) In the electrophilic substitution of arenes, different substituents can direct to different ring positions. (i) Describe the directing effect o...
(a) Explain why amides are much weaker bases than amines. [2] (b) Fig. 9.1 shows the preparation of 2-phenylethylamine, C6H5CH2CH2NH2, by three di...
The concentration of aqueous chloride ions can be found by titration with aqueous silver nitrate, AgNO3(aq). Ag+(aq) + Cl-(aq) → AgCl(s) The indica...
Effusion is the process in which a gas escapes through a small hole. A student investigates the relationship between rate of effusion and relative ...
Aqueous silver ions, Ag+(aq), react slowly with aqueous iron(II) ions, Fe2+(aq). An equilibrium is established. Ag+(aq) + Fe2+(aq) ⇋ Ag(s) + Fe3+(a...
A student carries out an experiment to determine the concentration of aqueous sulfate ions, SO42-(aq), in a sample of lake water.
A student has drawn a cell structure as seen using a light microscope. The magnification of the drawing is ×600. The length of the structure on the...
The electron micrograph shows part of a eukaryotic cell. Which of the labelled organelles is a site of protein synthesis? [Figure 2.1]
Inside a cell, a damaged mitochondrion can be surrounded and enclosed by a membrane to form a vesicle. What happens after the fusion of a lysosome ...
Which units are the most appropriate to record the diameter of a lymphocyte and a red blood cell? [Figure 4.1]
Which structures will be present in a cell that causes cholera? 1 circular DNA 2 naked DNA 3 70S ribosomes
What may take place during a hydrolysis reaction? 1 a molecule of water is produced 2 a glycosidic bond is broken 3 a sucrose molecule is split int...
The table shows some information about four carbohydrate polymers. Which two polymers form starch? [Figure 7.1]
Which molecule in the key is sucrose? [Figure 8.1]
Which statements about triglycerides and phospholipids are correct? 1 Triglycerides and phospholipids both have a hydrophobic region. 2 Triglycerid...
When proteins are mixed with some organic solvents, hydrophobic interactions and hydrogen bonding are changed in the protein molecules. Which level...
The rate of enzyme-catalysed reactions in human cells is regulated. What may be involved in such regulation? 1 a change in enzyme concentration 2 a...
The graphs show the effects of temperature and pH on enzyme activity. Which statement is a correct explanation of the enzyme activity? [Figure 12.1]
Which statement correctly describes the action of competitive enzyme inhibitors?
Which row correctly links molecules in the cell surface membrane with their roles? [Figure 14.1]
Antimycin is a chemical that inhibits the function of mitochondria. Which methods of transport across the cell surface membrane would be inhibited ...
Which statements about the cell cycle are correct? 1 The cell cycle consists of both interphase and mitosis. 2 DNA replication takes place in inter...
The diagram shows cells in different stages of the cell cycle. Which is the last stage before cytokinesis? [Figure 17.1]
How many of the listed structures typically contain genetic material that has telomeres? • bacterial cell • chloroplast • mitochondrion • nucleus
What does the enzyme DNA polymerase synthesise in a cell?
21.2% of the bases in a molecule of DNA are cytosine. What percentage would be adenine?
One gene provides the code for the production of which type of molecule?
The table shows the mode of action of two antibacterial drugs that can affect the synthesis of proteins. If bacteria are treated with both drugs, w...
The diagrams show transverse sections of parts of a plant. In the transverse sections, which tissues transport sucrose? [Figure 23.1]
Which statement describes movement through a plant in the apoplast pathway?
Which changes to the water potential and the volume of liquid in the phloem occur when sucrose is moved from the phloem sieve tube to an actively d...
The diagram shows the results of an experiment using leaves with the same surface area from two different species of plant. Each leaf was left on a...
Which evidence supports the cohesion-tension theory for the movement of water in flowering plants? 1 When the rate of transpiration of a tree is at...
Cardiac muscle is made up of many fibres that form the walls of the chambers of the heart. When the heart contracts, these fibres shorten in length...
Which reactions take place at a higher rate in a capillary in an alveolus than in a capillary in active muscle? 1 carbon dioxide + water → carbonic...
The diagram shows the effect of three different concentrations of carbon dioxide on the oxygen dissociation curve for human haemoglobin. What effec...
The graph shows the changes that take place in the volume of the left ventricle during one cardiac cycle. Which point on the graph represents the s...
The following tissues carry an electrical impulse during the cardiac cycle. 1 atrioventricular node 2 muscle wall of atria 3 Purkyne tissue 4 sinoa...
Some of the effects of smoking are listed. 1 It causes coughing. 2 It increases blood pressure. 3 It decreases the transport of oxygen. 4 It increa...