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Which process causes the greatest increase in the distance between particles?
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A student put 25.0 cm^3 of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use to obtain the most accurate results?
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The results obtained from a chromatogram are shown.
[Table_1]
Which row gives the $R_f$ values of substance X and substance Y?
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Two statements about silicon(IV) oxide are given.
1. It is a hard substance.
2. It has a macromolecular structure with strong covalent bonds.
Which is correct?
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Which statement explains why isotopes of the same element have the same chemical properties?
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Which dot-and-cross diagram shows the outer shell electron arrangement in a molecule of nitrogen?
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The equation for the reaction between barium chloride solution and dilute sulfuric acid is shown.
$BaCl_2 + H_2SO_4 \rightarrow BaSO_4 + 2HCl$
Which row shows the state symbols for this equation?
[Table_1]
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A compound is analysed and found to contain 85.7% carbon and 14.3% hydrogen.
What is its empirical formula?
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Which statements about the electrolysis of concentrated copper(II) chloride are correct?
1. Electrons are transferred from the cathode to the copper(II) ions.
2. Electrons move round the external circuit from the cathode to the anode.
3. Chloride ions are attracted to the anode.
4. Hydroxide ions transfer electrons to the cathode.
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Which metal combination produces the highest voltage reading in the cells shown?
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The compound hydrazine is used as a rocket fuel. It has the structural formula shown.
One of the reactions of hydrazine is shown. This reaction is exothermic.
$$\text{N}_2\text{H}_4 \rightarrow \text{N}_2 + 2\text{H}_2$$
The bond energies are shown in the table. [Table_1]
What is the energy change for this reaction?
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Which statement describes an exothermic reaction?
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The mass of a beaker and its contents is plotted against time.
Which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?
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Copper(II) oxide reacts with hydrogen.
$$\text{CuO} + \text{H}_2 \rightarrow \text{Cu} + \text{H}_2\text{O}$$
Which row is correct?
[Table_1]
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Ethanoic acid reacts slowly with calcium carbonate.
Which statements explain why an increase in temperature increases the rate of the reaction?
1 The activation energy of the reaction is decreased.
2 There is an increase in collision rate.
3 The particles have more energy.
4 There will be fewer successful collisions.
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Methane reacts with steam to produce hydrogen and carbon monoxide.
The equation for the reaction is shown.
$\text{CH}_4(g) + \text{H}_2\text{O}(g) \iff 3\text{H}_2(g) + \text{CO}(g)$
The reaction is reversible. The forward reaction is endothermic.
Which changes in temperature and pressure increase the equilibrium yield of carbon monoxide?
[Table_1]
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Some properties of four oxides are listed.
Oxide 1 reacts with both acids and alkalis to form salts.
Oxide 2 reacts with acids to form salts but does not react with alkalis.
Oxide 3 reacts with alkalis to form salts but does not react with acids.
Oxide 4 does not react with acids or alkalis.
Which row describes the oxides?
[Table_1]
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What is not a typical characteristic of acids?
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Zinc sulfate is made by reacting an excess of zinc oxide with dilute sulfuric acid.
The excess zinc oxide is then removed from the solution.
Which process is used to obtain solid zinc sulfate from the solution?
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Which statements about the trends across a period of the Periodic Table are correct?
1. Aluminium is more metallic than sodium.
2. Beryllium is more metallic than carbon.
3. Boron is more metallic than lithium.
4. Magnesium is more metallic than silicon.
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Astatine is an element in Group VII of the Periodic Table.
Astatine is ......1...... reactive than iodine.
The melting point of astatine is ......2...... than the melting point of iodine.
Astatine is ......3...... in colour than bromine.
Which words complete gaps 1, 2 and 3?
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Which row describes the properties of a typical transition element?
[Table 1]
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Why is argon gas used to fill electric lamps?
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Aluminium is extracted by the electrolysis of aluminium oxide. Which statement is not correct?
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Which row describes how the metals are used?
[Table_1]
mixed with zinc to form brass | used to galvanise iron
A. aluminium | tin
B. aluminium | zinc
C. copper | tin
D. copper | zinc
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Information about the nitrates and carbonates of two metals, Q and R, is shown.
[Table_1]
Which statement is correct?
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The flow chart shows stages in the treatment of river water to produce drinking water.
What occurs at stages X and Y?
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Four iron nails had different metals wrapped around them. The nails were placed in an open dish filled with water and left for a week. Which iron nail has no protection against rusting?
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Ammonia is made by the Haber process.
\( N_2 + 3H_2 \rightleftharpoons 2NH_3 \)
What are the sources of the nitrogen and hydrogen used in the Haber process?
[Table_1]
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Which process does not produce carbon dioxide?
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Which row shows the conditions used in the manufacture of sulfuric acid by the Contact process?
[Table_1]
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Some marble chips (calcium carbonate) are heated strongly and substances X and Y are formed.
Substance X is a white solid that reacts with water, giving out heat. Substance Y is a colourless gas.
What are substances X and Y?
[Table_1]
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The structures of some organic molecules are shown.
Which structures represent an alkane with four carbon atoms?
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Some of the fractions obtained from the fractional distillation of petroleum are used as fuels for vehicles.
Which two fractions are used as fuels for vehicles?
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X, Y and Z are three hydrocarbons.
X \( \text{CH}_2=\text{CH}_2 \) Y \( \text{CH}_3-\text{CH}=\text{CH}_2 \) Z \( \text{CH}_3-\text{CH}_2-\text{CH}=\text{CH}_2 \)
What do compounds X, Y and Z have in common?
1 They are all alkenes.
2 They are all part of the same homologous series.
3 They all have the same boiling point.
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The diagram shows a reaction sequence.
Which row names the processes X, Y and Z?
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Which pair of compounds can be used to prepare $CH_3CH_2COOCH_2CH_3$?
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The structure of a synthetic polymer is shown.
The structure shows that it is a ......1...... . It is formed by ......2...... polymerisation.
Which words complete gaps 1 and 2?
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