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Four physical changes of ethanol are listed. 1. condensation 2. evaporation 3. freezing 4. boiling In which changes do the particles move further apart?
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Which statement explains why water is a compound?
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An atom of element X contains: • 5 protons • 6 neutrons • 5 electrons.
Which statements about element X are correct?
1. X has an atomic number of 6.
2. X has a nucleon number of 11.
3. X is in Group II of the Periodic Table.
4. X is in the second period of the Periodic Table.
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Which row describes properties of lithium fluoride? [Table_1]
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Ammonia, NH$_3$, is a covalent molecule. Which diagram shows the outer-shell electron arrangement in a molecule of ammonia?
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Which substance has a giant covalent structure?
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Sodium burns in oxygen to form sodium oxide.
What is the balanced equation for the reaction?
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What is the relative formula mass of Mg(OH)_2?
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Dilute sulfuric acid is electrolysed using inert electrodes. The apparatus is set up as shown.
30 cm$^3$ of a gas is collected at the cathode. A different gas is collected at the anode.
Which row is correct?
[Table_1]
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Four statements about hydrogen fuel cells are listed.
1. The fuel cell converts chemical energy into electrical energy.
2. In the fuel cell, hydrogen combines with oxygen.
3. Carbon dioxide and water are produced in the fuel cell.
4. The hydrogen fuel is extracted from the air.
Which statements are correct?
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5 g of four different fuels are set alight and placed under a beaker containing 50 \text{ cm}^3 of water. The temperature of the water is taken at the start and after five minutes. Which fuel releases the most energy? [Table_1]
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Which changes increase the rate of reaction?
1. increasing the concentration of the reactants
2. increasing the particle size of a solid reactant
3. increasing the temperature
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Which reaction is reversible?
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The equation for the reaction between iron(III) oxide and carbon is shown. $$2Fe_2O_3 + 3C \rightarrow 4Fe + 3CO_2$$ Which type of reaction does iron(III) oxide undergo?
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Copper(II) chloride is made when copper(II) carbonate reacts with dilute hydrochloric acid.
What are the other products in this reaction?
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Rubidium is in Group I and strontium is in Group II of the Periodic Table.\nWhich row describes the nature of rubidium oxide, $Rb_2O$, and strontium oxide, $SrO$? [Table_1]
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Magnesium sulfate is a soluble solid which is formed when insoluble magnesium oxide reacts with dilute sulfuric acid. Which method is used to prepare solid magnesium sulfate?
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Q and R are elements in the same period of the Periodic Table. Q has 7 electrons in its outer shell and R has 2 electrons in its outer shell. Which statement about Q and R is correct?
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Which statement about alkali metals is correct?
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Aqueous bromine is added to aqueous sodium iodide.
bromine + sodium iodide \rightarrow ......1...... + ......2......
What are the products of this reaction? [Table_1]
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Which row describes the properties of a transition element? [Table_1]
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Which row describes the properties of argon? [Table_1] | | property 1 | property 2 | |--------|------------|------------| | **A** | inert | diatomic | | **B** | inert | monatomic | | **C** | reactive | diatomic | | **D** | reactive | monatomic |
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Which row identifies the properties of zinc? [Table_1]
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Uses of metals depend on their properties. Which property is necessary for the use given? [Table_1]
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Which compounds \textbf{both} contribute to acid rain?
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P, Q, R and S are metals.
P reacts with dilute hydrochloric acid, forming hydrogen.
Q reacts violently with water.
R reacts with water to give hydrogen.
S is formed by heating its oxide with carbon.
Which row identifies the metals?
[Table_1]
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Which compound is formed when iron rusts?
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Which reaction in the blast furnace releases heat energy?
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A wax candle is made from a mixture of hydrocarbons.
The candle is lit and placed in a gas jar along with a strip of cobalt(II) chloride test paper as shown.
After a short time, the oxygen in the jar is used up and the candle flame goes out.
Which substance does the cobalt(II) chloride paper identify?
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Urea, CO(NH_2)_2, is used as a fertiliser.
Which element that plants need for improved plant growth is provided by urea?
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The percentage composition of gases on Neptune is shown. [Table_1]
Which statement about the atmospheres on Neptune and on the Earth is correct?
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Which row shows the general formula for alkenes and for alcohols? [Table_1]
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A molecule has the formula $C_2H_5Cl$. What is its chemical name?
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Which compound rapidly decolourises aqueous bromine?
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Compound Z has the molecular formula $C_2H_6O$.
Which statement about compound Z is correct?
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What is the formula of the salt formed when aqueous ethanoic acid reacts with calcium carbonate?
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Rock salt is a mixture of salt and sand. The method used to separate the sand from the salt is listed.
step 1 Crush the rock salt, add to warm water and stir.
step 2 Pour the mixture through a filter paper held in a funnel.
step 3 Evaporate the water to crystallise the salt.
Which statement about the method is correct?
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Chromatography is carried out on mixture Y and dyes E, F, G, and H. The chromatogram is shown. Which dyes are present in mixture Y?
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A fractionating column is used to separate the hydrocarbon fractions in petroleum by fractional distillation.
Which row describes the properties of the fractions that condense at the top of the fractionating column?
[Table_1]
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When acid is added to salt X, a gas is produced which turns limewater milky.
When sodium hydroxide is added to salt X, a gas is produced which turns litmus paper blue.
What is X?
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