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A 1 cm$^3$ sample of substance X is taken. This is sample 1.
X is then converted to a different physical state and a 1 cm$^3$ sample is taken. This is sample 2.
Sample 2 contains more particles in the 1 cm$^3$ than sample 1.
Which process caused this increase in the number of particles in 1 cm$^3$?
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Solid carbon dioxide changes directly into a gas under suitable conditions of temperature and pressure.
Carbon dioxide gas moves from a high concentration to a low concentration.
Which row names these two processes?[Table_1]
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598
Which statement about paper chromatography is correct?
503
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566
Element X has 7 protons.
Element Y has 8 more protons than X.
Which statement about element Y is correct?
516
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505
A covalent molecule Q contains only six shared electrons.
What is Q?
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Which piece of apparatus is used to measure exactly 25.00 cm3 of hydrochloric acid?
591
568
591
Which statement about isotopes of the same element is correct?
507
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527
Potassium reacts with iodine to form an ionic compound.
$$2K + I_2 \rightarrow 2KI$$
Which statements describe what happens when potassium reacts with iodine?
1. Each potassium atom loses two electrons.
2. Each potassium atom loses one electron.
3. Each iodine atom gains one electron.
4. Each iodine atom gains two electrons.
519
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562
What is the relative formula mass of magnesium nitrate, $\text{Mg(NO}_3\text{)}_2$?
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In separate experiments, electricity was passed through concentrated aqueous sodium chloride and molten lead(II) bromide. What would happen in \textbf{both} experiments?
505
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The equation for the decomposition of calcium carbonate is shown.
$\text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2$
What mass of calcium oxide is produced when 10 g of calcium carbonate is heated?
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Heat energy transfer during chemical reactions can be described using energy level diagrams. In which row is the description correct? [Table_1]
509
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The equations for two reactions are shown.
1 $\text{ }$ $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$
2 $\text{ }$ $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$
Which statement about the reactions is correct?
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When sulfur is heated it undergoes a ......1...... change as it melts.
Further heating causes the sulfur to undergo a ......2...... change and form sulfur dioxide.
Which words complete gaps 1 and 2?
[Table_1]
520
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505
Copper(II) carbonate reacts with dilute sulfuric acid.
Which conditions produce the fastest rate of reaction?
[Table_1]
575
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507
Hydrated copper(II) sulfate is blue. When it is heated it forms white anhydrous copper(II) sulfate. How is a sample of anhydrous copper(II) sulfate changed into hydrated copper(II) sulfate?
559
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Copper(II) oxide reacts with iron. The equation for the reaction is shown.
$3\text{CuO} + 2\text{Fe} \rightarrow 3\text{Cu} + \text{Fe}_2\text{O}_3$
Why can this reaction be described as the reduction of copper(II) oxide?
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Element X forms an oxide, XO, that neutralises sulfuric acid.
Which row describes X and XO?
[Table_1]
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Which methods of salt preparation are suitable for copper(II) chloride?
1. Add copper(II) carbonate to dilute hydrochloric acid.
2. Add copper to dilute hydrochloric acid.
3. Warm copper(II) oxide with dilute hydrochloric acid.
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A white solid, J, is tested and the observations are shown.
[Table_1]
What is J?
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Which statement about the Periodic Table is not correct?
541
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552
Bromine and iodine are elements in Group VII of the Periodic Table.
Which statement about these elements is correct?
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Helium and neon exist as monoatomic gases at room temperature and pressure.
statement 1 Helium and neon have eight electrons in their outer shell.
statement 2 Helium and neon are unreactive.
Which option is correct?
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An element melts at 1455 °C, has a density of 8.90 g/cm³ and forms a green chloride.
Where in the Periodic Table is this element found?
[Image_1: Periodic Table with labeled positions A, B, C, D]
553
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Which statement about the reactivity of metals is correct?
587
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592
Iron from a blast furnace is treated with oxygen and with calcium oxide to make steel. Which substances in the iron are removed? [Table_1]
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Water is removed from reservoirs and undergoes several stages of treatment to make it suitable for drinking.
Which statements about the stages are correct?
1. Chlorine is added to the water to kill harmful bacteria.
2. Water is heated to remove dissolved oxygen gas.
3. Water is filtered to remove solids.
539
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502
Which gas is an air pollutant that causes acid rain?
508
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547
An NPK fertiliser is made by mixing two compounds.
The first compound has the formula $(NH_4)_2HPO_4$.
What is the formula of the second compound?
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Which reaction does not occur during the extraction of iron from hematite in a blast furnace?
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Which row describes the uses of sulfur and sulfur dioxide? [Table_1]
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Metal X is a good conductor of electricity and is used for electrical wiring.
Metal Y is used to make an alloy which is resistant to corrosion and is used to make cutlery.
Metal Z is light and strong and is used in the manufacture of aircraft.
What are X, Y and Z?
[Table_1]
557
516
563
Which statement about calcium carbonate is correct?
596
524
552
What is the main constituent of natural gas?
518
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512
Which compounds belong to the same homologous series?
598
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539
Which statement about alkanes is correct?
599
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537
P, Q, R and S are organic compounds.
P is formed by reacting ethene with steam.
Q decolourises bromine water.
R is a hydrocarbon; all of its bonds are single covalent bonds.
S is a waste product from digestion in animals.
Which compounds are alkanes?
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513
Which row describes how ethanol is used?
[Table_1]
541
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563
Which diagram shows the conversion of ethene into ethanol?
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