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Decane has a freezing point of $-30^{\circ}\text{C}$ and a boiling point of $174^{\circ}\text{C}$.
A small sample of decane is placed in an open beaker in an oven at a temperature of $120^{\circ}\text{C}$ and at atmospheric pressure for 24 hours.
What happens to the sample of decane?
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A student put exactly 25.00 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?
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A student separates sugar from pieces of broken glass by dissolving the sugar in water and filtering off the broken glass.
What is the filtrate?
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Two isotopes of carbon are $^{12}\text{C}$ and $^{14}\text{C}$.
Which statement about these two isotopes is correct?
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The element livermorium, Lv, was discovered in the year 2000.
Which statement predicts what will happen to an Lv atom when it forms an $\text{Lv}^{2-}$ ion?
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Which substance is a diatomic covalent compound?
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The formula of sodium chlorate(V) is NaClO$_3$.
What is the relative formula mass of sodium chlorate(V), NaClO$_3$?
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Which statements about the products of electrolysis, using inert electrodes, are correct?
1 When molten lead(II) bromide is electrolysed, bromine is formed at the cathode.
2 When dilute sulfuric acid is electrolysed, oxygen is formed at the anode.
3 When concentrated aqueous sodium chloride is electrolysed, sodium is formed at the cathode.
4 When concentrated hydrochloric acid is electrolysed, chlorine is formed at the anode.
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The temperature decreases when aqueous ethanoic acid reacts with solid sodium carbonate to form a salt.
Which type of reaction and energy change occur?
[Table_1]
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Solid copper(II) carbonate reacts with dilute sulfuric acid.
\( \text{CuCO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{CuSO}_4 + \text{CO}_2 + \text{H}_2\text{O} \)
The rate of the reaction can be changed by varying the conditions.
Which changes always increase the rate of this chemical reaction?
1 increasing the concentration of sulfuric acid
2 increasing the size of the pieces of copper(II) carbonate
3 increasing the temperature
4 increasing the volume of sulfuric acid
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Some changes are shown in the table.
In which rows are the changes described correctly?
[Table_1]
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X is a pink solid. Y is a blue solid. When X is heated, water is produced and the solid turns blue. When water is added to Y, the solid turns pink. What are X and Y? [Table_1]
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Carbon reacts with carbon dioxide as shown.
$\text{CO}_{2} + \text{C} \rightarrow 2\text{CO}$
Which statement about this reaction is correct?
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Which substances do not produce water as a product when they are reacted together?
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The surface of magnesium ribbon reacts with the air to form magnesium oxide.
Which statement explains why the layer of magnesium oxide is removed by dilute hydrochloric acid?
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Copper(II) chloride crystals are made by adding solid copper(II) carbonate to dilute hydrochloric acid until no more dissolves. Which process is used to obtain pure copper(II) chloride crystals from the mixture?
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Which statement about aqueous sodium hydroxide is correct?
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A period of the Periodic Table is shown.
[Table_1]
The letters are not their chemical symbols.
Which statement is correct?
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What are the products of the reaction between sodium and water?
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Element X has a high density, a high melting point and a high electrical conductivity.
It forms many coloured compounds.
Element X and many of its compounds act as catalysts.
What could be the atomic number of X?
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The noble gases are in Group VIII of the Periodic Table.
Which statement explains why noble gases are unreactive?
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Which statement is correct for all metals?
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Which statement about the extraction of metals is correct?
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Which row identifies a use of mild steel and a use of stainless steel?
[Table_1]
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The diagrams show some uses of water in the home.
For which uses is it important for the water to have been treated?
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Which air pollutants can cause damage to buildings made of limestone?
1. carbon monoxide
2. lead compounds
3. oxides of nitrogen
4. sulfur dioxide
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Which statement about fertilisers is correct?
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Sulfur burns to make sulfur dioxide.
Which row describes a source of sulfur and a use of sulfur dioxide?
[Table_1]
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Lime (calcium oxide) is used to treat waste water from a factory.
Which substance is removed by the lime?
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Fuel X produces carbon dioxide and water when it is burned in air. So does fuel Y. What could X and Y be? [Table_1]
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Which hydrocarbon is the main constituent of natural gas?
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Which statements about ethene are correct?
1. It contains a C=C bond.
2. It does not decolourise bromine water.
3. Its molecules can join together to form long chain compounds.
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Part of the structure of a very large molecule is shown.
Which term describes the small unit used to make this molecule?
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What is the total number of single covalent bonds in a molecule of ethanol?
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Which statement about aqueous ethanoic acid is correct?
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Three statements about synthetic polymers are listed.
1. Man-made fibres are used for making clothing.
2. Plastics can cause pollution problems both on land and at sea.
3. Plastics which do not rot away are described as non-biodegradable.
Which statements are correct?
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