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Which gas has the slowest rate of diffusion?
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When a dark grey solid element is heated, it changes directly into a purple gas. Which word describes this change?
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Nickel(II) sulfate is a green solid that is soluble in water.
Which method is used to obtain a pure sample of nickel(II) sulfate crystals from a mixture of nickel(II) sulfate and sand?
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In the chromatography experiment shown, which label represents the solvent front?
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Molecules containing only non-metal atoms are covalently bonded.
The formulae of four covalently bonded molecules are given below:
1 nitrogen, $N_2$
2 carbon dioxide, $CO_2$
3 ethene, $C_2H_4$
4 methanol, $CH_3OH$
Which of the molecules contain double bonds?
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The arrangements of the electrons in two ions formed from elements X and Y are shown.
Which equation represents the reaction between elements X and Y?
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Magnesium reacts with sulfuric acid.
What are the formulae of the products formed in this reaction?
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Sodium reacts with chlorine to form sodium chloride.
Which row describes the bonding in the three substances?[Table_1]
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Rubidium is in Group I of the Periodic Table and bromine is in Group VII.
Rubidium reacts with bromine to form an ionic compound.
Which row shows the electron change taking place for rubidium and the correct formula of the rubidium ion?
[Table_1]
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Which statement explains why graphite is used as a lubricant?
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The relative atomic mass of chlorine is 35.5.
When calculating relative atomic mass, which particle is the mass of a chlorine atom compared to?
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What is the empirical formula of an oxide of iron, formed by reacting 2.24 g of iron with 0.96 g of oxygen?
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Electrolysis is carried out on dilute aqueous potassium bromide.
Which products are formed at the anode and the cathode?
[Table_1]
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Which substance does not require oxygen in order to produce energy?
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Ethanol is used as a fuel.
ethanol + oxygen \rightarrow carbon dioxide + water
Which statements are correct?
1. The reaction is endothermic.
2. The products have more energy than the reactants.
3. The oxygen for this reaction comes from the air.
4. The temperature of the reaction mixture rises during this reaction.
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The reaction between hydrogen and oxygen releases 486 kJ/mol of energy.
$$2H_2(g) + O_2(g) \rightarrow 2H_2O(g)$$
The bond energy of H–H is 436 kJ/mol and that of H–O is 464 kJ/mol.
What is the bond energy of O=O?
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Which reaction of hydrochloric acid is a redox reaction?
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Which reaction is an example of a photochemical reaction?
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An excess of calcium carbonate is added to dilute hydrochloric acid, X.
The carbon dioxide gas given off is collected and its volume recorded at regular time intervals.
Line X on the graph shows the results obtained.
The experiment is repeated using dilute hydrochloric acid, Y.
Line Y on the graph shows the results obtained.
Which statement about the two hydrochloric acid samples, X and Y, is correct?
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Period 3 of the Periodic Table contains the elements sodium to argon.
Element Q is a non-metal from this period.
Which statement about Q is correct?
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Which metal has variable oxidation states?
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An aqueous cation reacts with aqueous sodium hydroxide to form a white precipitate.
The precipitate is insoluble in excess sodium hydroxide.
What is the aqueous cation?
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Zinc oxide is an amphoteric oxide.
Which row describes the reactions of zinc oxide?
[Table_1]
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A student carries out an experiment to prepare pure magnesium sulfate crystals. The diagram shows the first stage of the preparation. He adds magnesium carbonate until no more reacts. Which process should he use for the next stage?
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Which statement about the halogens and their compounds is correct?
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Elements in Group II of the Periodic Table show the same trends in their reaction with water and their density as Group I.
Which row shows how the properties of barium compare with calcium?
[Table with headings 'reaction with water' and 'density': A. faster, higher; B. faster, lower; C. slower, higher; D. slower, lower]
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A flammable gas needs to be removed from a tank at an industrial plant. For safety reasons, an inert gas is used. Which gas is suitable?
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An experiment is performed to determine the order of reactivity of metals X and Y compared to lead.
Strips of each metal were added to separate test-tubes containing aqueous lead(II) nitrate, $\text{Pb(NO}_3\text{)}_2$.
The results are shown.
What is the order of reactivity, least reactive first?
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The equation for the reaction between iron(III) oxide and carbon monoxide is shown.
$\text{Fe}_2\text{O}_3 + x\text{CO} \rightarrow y\text{Fe} + z\text{CO}_2$
Which values of x, y and z balance the equation?
[Table_1]
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Which process is used to separate oxygen from liquid air?
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What is the catalyst in the Haber process?
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Ammonia is manufactured in an exothermic reaction.
$\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g)$
What is the effect of lowering the pressure on the rate of formation of ammonia and percentage yield of ammonia at equilibrium?
[Table_1]
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Part of the carbon cycle is shown.
What are processes P, Q, and R?
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Which row shows the conditions used for the manufacture of sulfuric acid in the Contact process?
[Table_1]
511
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579
Which calcium compound does not neutralise an acid soil?
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Which product is obtained when bromine reacts with propene, $\text{CH}_3\text{CH}=\text{CH}_2$?
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Propanol is oxidised by acidified potassium manganate(VII) in a similar way to ethanol.
Which compound is produced by the oxidation of propanol with acidified potassium manganate(VII)?
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The flow chart shows the preparation of ethanol and some important chemistry of ethanol.
What are X, Y, and Z?
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Which equation represents the formation of poly(propene) from propene?
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Which type of linkage joins the amino acids in a protein?
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