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The diagram shows the changes of state between a solid, a liquid and a gas.
In which changes of state is energy being given out?
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A coloured dye is separated by chromatography.
One component of the dye moves a distance of 13 cm and has an $R_f$ value of 0.86.
Which distance did the solvent front move?
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A mixture contains salt, sand and sulfur.
Salt dissolves in water but not in xylene.
Sulfur dissolves in xylene but not in water.
Sand does not dissolve in water or xylene.
What is the order of the processes used to separate the salt, the sand and the sulfur from the mixture?
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Which statements about isotopes of the same element are correct?
1. They are atoms which have the same chemical properties because they have the same number of electrons in their outer shell.
2. They are atoms which have the same number of electrons and neutrons but different numbers of protons.
3. They are atoms which have the same number of electrons and protons but different numbers of neutrons.
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Which type of structure and bonding is present in an element that is malleable and conducts electricity?
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Which statements about potassium bromide are correct?
1. It has a high melting point.
2. It dissolves in water.
3. It conducts electricity when solid.
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Which substance has a similar structure to silicon(IV) oxide?
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Caffeine is a stimulant found in coffee.
[Image_1: Structure of caffeine]
Which formula represents caffeine?
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4.55 g of zinc is reacted with 50 cm3 of 2.25 mol/dm3 dilute hydrochloric acid.
The equation for the reaction is shown.
$\text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2$
Which volume of hydrogen gas, at room temperature and pressure, is produced in the reaction?
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In the electrolysis diagram, oxidation is occurring at electrode 1 and reduction at electrode 2.
Which row shows the directions of movement of the electrons in the external circuit and of the positive ions in the electrolyte?
[Table_1]
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When an acid is added to an alkali, the temperature of the reaction mixture rises.
Which words describe this reaction?
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Some properties of four fuels are shown. Which fuel is a gas at room temperature and makes two products when it burns in a plentiful supply of air?
[Table_1]
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Ethene can undergo complete combustion, as shown.
Some bond energies are given in the table.
[Table_1]
The energy change of the reaction is −1408 kJ/mol.
What is the bond energy of the C=O bond in CO₂?
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A student adds excess zinc to dilute hydrochloric acid at 25°C. The hydrogen gas produced is collected and measured at room temperature and pressure. The results are plotted and labelled as curve X on the graph. The experiment is repeated at 50°C with all other conditions remaining the same. Which graph shows the results at 50°C?
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Dinitrogen tetroxide, $\text{N}_2\text{O}_4$, is converted into nitrogen dioxide, $\text{NO}_2$, in a reversible reaction.
$\text{N}_2\text{O}_4(g) \rightleftharpoons 2\text{NO}_2(g)$
The forward reaction is endothermic.
Which conditions give the highest equilibrium yield of nitrogen dioxide? [Table_1]
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When magnesium is heated with zinc oxide a reaction occurs. The equation is shown.
$\text{Mg} + \text{ZnO} \rightarrow \text{MgO} + \text{Zn}$
Which substance is oxidised?
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The diagram shows an experiment.
A small volume of aqueous P is poured on to solid Q and the tap of the funnel closed.
Which pairs of substances cause the syringe to fill with gas?
[Table_1]
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Ethanoic acid reacts with water to produce an acidic solution.
Which row describes the roles of ethanoic acid and water in this reaction?
[Table_1]
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Aqueous ammonium sulfate is made by reacting aqueous ammonia with dilute sulfuric acid.
How is solid ammonium sulfate obtained from the resulting solution?
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Carbon forms two oxides: carbon monoxide, CO, and carbon dioxide, CO₂.
Which row describes these two oxides?
[Table_1]
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Group II elements show the same trends as Group I elements.
Which statement about elements in Group II is correct?
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Some information about properties of Group I elements is shown.
[Table_1]
What are the values for X, Y and Z?
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Which statements describe properties of transition elements?
1. They form coloured compounds.
2. They have variable oxidation states.
3. They have low densities.
4. They are volatile.
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Which statement about the extraction of aluminium by electrolysis is correct?
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Copper(II) nitrate and zinc carbonate are heated strongly in separate test-tubes. Which row identifies the gases produced?
[Table_1]
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Iron from a blast furnace can be converted to steel. Which statements about steel are correct?
1. Steel contains more carbon than the iron obtained from the blast furnace.
2. Steel is produced by blowing oxygen through the iron.
3. Calcium oxide is added to molten iron to remove basic oxides.
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Which metal is used to galvanise steel?
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The diagram shows a stage in the purification of dirty water. Which process does this apparatus show?
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Which substance in polluted air damages stonework and kills trees?
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Which row explains why a high temperature and an iron catalyst are used in the manufacture of ammonia by the Haber process?
[Table_1]
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The scheme shows four stages in the conversion of sulfur to sulfuric acid. In which stage is a catalyst used?
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Which element has an oxide that is used as a food preservative?
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Which substance gives off carbon dioxide on heating?
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518
Which statement about structural isomers is correct?
510
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524
Which formula is the same in methanol, ethanol and propanol?
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Ethene reacts with water under suitable conditions.
Which statement about this reaction is correct?
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Ethanoic acid is made by reacting ethanol with acidified potassium manganate(VII).
Which type of reaction occurs when ethanol reacts with acidified potassium manganate(VII)?
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The equation shows the formation of a polymer called Kevlar.
Which row describes Kevlar?
[Table_1]
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