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The chromatogram from four different substances is shown. Which pure substance has the largest $R_f$ value?
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The structure of sodium chloride can be represented as shown. What are X and Y? [Table_1]
570
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596
Which two particles have the same electronic structure?
528
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550
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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513
What is the total number of shared electrons in a molecule of methanol, CH$_3$OH?
599
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Which row about the structures and uses of diamond and graphite is correct?
[Table_1]
552
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511
Caffeine is a stimulant found in coffee.
Which formula represents caffeine?
561
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The equation for the reaction between hydrogen sulfide, $\text{H}_2\text{S}$, and oxygen is shown.
$$2\text{H}_2\text{S} + 3\text{O}_2 \rightarrow 2\text{SO}_2 + 2\text{H}_2\text{O}$$
Which mass of oxygen is required to react with 5.1 g of hydrogen sulfide?
557
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591
Which apparatus is used to plate a nickel object with silver?
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When an acid is added to an alkali, the temperature of the reaction mixture rises. Which words describe this reaction?
536
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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]
513
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583
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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Dilute hydrochloric acid is reacted with excess calcium carbonate and the total volume of gas is measured at regular intervals. The results are shown by line W on the graph. The experiment is repeated but with one change. The results of the second experiment are shown by line X on the graph.
Which change is made in the second experiment?
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When hydrated copper(II) sulfate is heated, it produces white copper(II) sulfate. When water is added, the white copper(II) sulfate turns blue. Which type of reaction is shown by these observations?
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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?
547
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The equation for the reaction between ethene and hydrogen is shown.
$$\text{CH}_2{=}\text{CH}_2(g) + \text{H}_2(g) \rightarrow \text{CH}_3{-}\text{CH}_3(g)$$
The bond energies are shown.
[Table_1]
What is the overall energy change during this reaction?
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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]
519
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Tests are done on an aqueous solution.
[Table_1]
Which cations produce these observations?
1. aluminium, $Al^{3+}$
2. calcium, $Ca^{2+}$
3. zinc, $Zn^{2+}$
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Ammonia, NH$_3$, dissolves in water to form a dilute solution of ammonium hydroxide, NH$_4$OH.
The reaction is reversible and exists as an equilibrium mixture.
$$\text{NH}_3(g) + \text{H}_2\text{O}(l) \leftrightarrow \text{NH}_4^+(aq) + \text{OH}^-(aq)$$
Which statement about the mixture is correct?
520
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Elements E and F are in Group I of the Periodic Table.
E has a higher melting point than F.
Elements J and L are in Group VII of the Periodic Table.
J has a higher density than L.
Which elements have the highest atomic numbers in each group?
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Which metal forms ions with one oxidation state?
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How does the nature of the oxides change across Period 3 from sodium to chlorine?
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Zinc is a metal with a boiling point of 907\(^{\circ}\)C.
Two methods of making zinc are shown.
Which statement is correct?
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537
Which statement about the reactions of metals is correct?
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12.4 g of copper(II) carbonate is heated in a test-tube. Only 50% is decomposed.
[M_r: \ CuCO_3, \ 124; \ CuO, \ 80]
What will be the final mass of the substances in the test-tube?
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Which statement about the manufacture of ammonia is correct?
535
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547
The diagram shows a stage in the purification of dirty water.
Which process does this apparatus show?
533
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528
Which substance in polluted air damages stonework and kills trees?
520
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512
Petrol-fuelled cars produce oxides of nitrogen.
Which statement explains how oxides of nitrogen are formed?
574
527
588
The scheme shows four stages in the conversion of sulfur to sulfuric acid.
In which stage is a catalyst used?
536
560
595
Which element has an oxide that is used as a food preservative?
500
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Which substance gives off carbon dioxide on heating?
535
555
501
Which formula represents ethyl butanoate?
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567
Methanol, $\text{CH}_3\text{OH}$, is a member of the homologous series of alcohols.
What is the formula of the alcohol in the same homologous series which contains three carbon atoms?
581
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Which type of compound reacts with hydrogen in an addition reaction?
558
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The equation for the reaction between methane and chlorine is shown.
$$\text{CH}_4 + 4\text{Cl}_2 \rightarrow \text{CCl}_4 + 4\text{HCl}$$
Which type of reaction does methane undergo?
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573
The structure of propene is shown.
Which diagram represents poly(propene)?
532
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533
The equation shows the formation of a polymer called Kevlar.
Which row describes Kevlar?
[Table_1]
553
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567
