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'Particles moving very slowly from an area of higher concentration to an area of lower concentration.'
Which process is being described?
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A student mixes 25 cm$^3$ samples of dilute hydrochloric acid with different volumes of aqueous sodium hydroxide. In each case, the student measures the change in temperature to test if the reaction is exothermic. Which piece of apparatus is not needed?
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A sample contains a mixture of powdered limestone (calcium carbonate), sugar and wax.
What is the correct way to obtain a pure sample of sugar?
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The table shows information about four different particles.
[Table_1]
What are the values of W, X, Y and Z?
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In which ionic compound do the metal ion and the non-metal ion have the same electronic structure?
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The structure of methanal is shown.
Which diagram shows the arrangement of outer shell electrons in a molecule of methanal?
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Iron is a metal. Its structure consists of a giant lattice of positive ions in a 'sea of electrons'.
Which statements about solid iron are correct?
1. Iron conducts electricity because the electrons are free to move.
2. Iron conducts heat because the positive ions are free to move.
3. Iron has a high melting point due to the strong covalent bonds.
4. Iron is malleable because the layers of ions can slide over one another.
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Which sample contains the greatest number of molecules?
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Sodium carbonate solution reacts with dilute hydrochloric acid. The equation for the reaction is shown.
$Na_2CO_3(aq) + 2HCl(aq) \rightarrow 2NaCl(aq) + CO_2(g) + H_2O(l)$
Excess sodium carbonate is added to 10.0 cm3 of 0.10 mol/dm3 hydrochloric acid.
Which volume of carbon dioxide gas is made?
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Which apparatus could be used to electroplate an iron nail with copper?
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A student sets up a number of simple cells by putting strips of two different metals into dilute sulfuric acid. Which cell produces the highest voltage?
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Which experiment is the most exothermic?
[Table_1]
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The energy level diagram for a reaction is shown.
Which row is correct?
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Zinc granules are reacted with excess dilute hydrochloric acid. The volume of hydrogen given off is measured at different times. The results are shown on the graph, labelled experiment 1. The results for a second experiment are also shown on the graph, labelled experiment 2.
Which change to the conditions was made in experiment 2?
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In an experiment nitric acid is added to excess marble chips and the volume of carbon dioxide formed is measured.
The experiment is repeated using smaller marble chips. All other conditions remain the same.
Which statement about the second experiment is correct?
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At 400°C the reaction between hydrogen and iodine reaches an equilibrium. The reaction is exothermic.
$$ \text{H}_2(g) + \text{I}_2(g) \rightleftharpoons 2\text{HI}(g) \quad \Delta H = -13 \text{kJ/mol} $$
Which change in conditions would increase the percentage of hydrogen iodide in the equilibrium mixture?
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Chromium forms the compound chromium(III) sulfate.
What does the (III) represent?
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Germanium oxide is a white powder. Germanium oxide reacts with concentrated hydrochloric acid. Germanium oxide reacts with concentrated aqueous sodium hydroxide. Germanium oxide does not dissolve when added to water. Which type of oxide is germanium oxide?
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Hydrogen chloride gas reacts with water to produce an acidic solution. The equation for the reaction is shown.
$\text{HCl} + \text{H}_2\text{O} \rightarrow \text{Cl}^- + \text{H}_3\text{O}^+$
Which statement describes what happens during the reaction?
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The apparatus shown is used to prepare aqueous copper(II) sulfate.
What are X and Y?
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Information about some silver compounds is shown in the table:
[Table_1]
Which equation shows a reaction which cannot be used to make a silver salt?
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What is not a property of Group I metals?
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Aqueous sodium hydroxide was added slowly, until in excess, to separate solutions of W, X, Y and Z. The results are shown.
[Table_1]
Which row identifies the metal ions in the solutions?
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Part of the Periodic Table is shown.
Which element has two electrons in its outer shell and three electron shells?
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Impurities in iron obtained from the blast furnace include carbon, phosphorus, and silicon.
Which impurities are removed from the molten iron as gases when it is made into steel?
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Y displaces X from its aqueous sulfate.
X does not displace W from its aqueous sulfate.
X displaces Z from its aqueous sulfate.
What is the order of reactivity of elements W, X, Y and Z?
[Table_1]
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Which statement about the industrial extraction of aluminium from aluminium oxide is correct?
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The alloy brass is a mixture of copper and another metal.
Brass is used to make the pins of electrical plugs.
Copper is used to make electrical wiring.
Which row about brass is correct?
[Table_1]
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Air is a mixture of gases.
Which gas is present in the largest amount?
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Which information about carbon dioxide and methane is correct? [Table_1]
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Boats made from steel can be protected from rusting by attaching blocks of a more reactive metal to the hull of the boat.
Which statement is correct?
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Ammonia is manufactured by the Haber process, using an iron catalyst.
$ \text{N}_2 + 3\text{H}_2 \rightleftharpoons 2\text{NH}_3 $
It is not possible to obtain 100% yield.
What is the reason for this?
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Sulfuric acid is manufactured by a series of chemical reactions, one of which is catalysed by vanadium(V) oxide.
What is the equation for the reaction catalysed by vanadium(V) oxide?
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Which substance gives off carbon dioxide on heating?
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Petroleum is separated into fractions.
Which statement is not correct?
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Butane reacts as shown.
What is this type of reaction?
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Substance Z has the following characteristics.
1. It burns in an excess of oxygen to form carbon dioxide and water.
2. It is oxidised by air to form a liquid smelling of vinegar.
3. It reacts with carboxylic acids to form esters.
What is substance Z?
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Ethanol is manufactured by the catalytic addition of steam to ethene and by fermentation. Which row shows an advantage and a disadvantage of using the catalytic addition of steam to ethene compared to fermentation?[Table_1]
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Chloroethene, $\text{CH}_2=\text{CHCl}$, can be polymerised.
Which diagram represents a section of the polymer?
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Terylene is a synthetic polymer.
Which statement about Terylene is \textbf{not} correct?
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