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An attempt was made to compress a gas and a solid using the apparatus shown.
Which substance would be compressed and what is the reason for this?
A student measures the rate of two reactions. In one reaction, there is a change in mass of the reactants during the reaction. In the second reaction, there is a change in temperature during the reaction. Which piece of apparatus would be essential in both experiments?
Diagram 1 shows the paper chromatogram of substance X.
Diagram 2 shows the cooling curve for substance Y.
Which statement about X and Y is correct?
Which statements about a sodium atom, $_{11}^{23} ext{Na}$, are correct?
1. The number of protons and neutrons is the same.
2. The number of protons and electrons is the same.
3. The number of outer electrons is one.
The diagrams show the electron arrangements in the atoms of four elements.
Which element does not form a covalent bond?
Rubidium is in Group I of the Periodic Table and bromine is in Group VII.
Rubidium reacts with bromine to form an ionic compound.
Which row shows the electron change taking place for rubidium and the correct formula of the rubidium ion?
[Table_1]
Element X has 7 protons.
Element Y has 8 more protons than X.
Which statement about element Y is correct?
The formulae of compounds W, X and Y are shown.
W \[ \text{CuSO}_4.5\text{H}_2\text{O} \]
X \[ \text{MgSO}_4.7\text{H}_2\text{O} \]
Y \[ \text{Cu(NO}_3)_2.6\text{H}_2\text{O} \]
Which statement is correct?
A solid mixture contains an ionic salt, X, and a covalent organic compound, Y.
Two students suggest methods of separating the mixture as shown.
Method 1: shake with water
Method 2: shake with ethanol
Which methods of separation are likely to work?
The diagram shows the circuit for electrolysing lead(II) bromide and sodium chloride to liberate the metal.
In what form are these salts electrolysed for liberating the metal?
Which relative molecular mass, $M_r$, is \textit{not} correct for the molecule given?
[Table_1]
When anhydrous copper(II) sulfate is added to water, a solution is formed and heat is given out.
Which row correctly shows the temperature change and the type of reaction taking place?
The diagram shows the electrolysis of concentrated aqueous sodium chloride.
What is the colour of the litmus at each electrode after five minutes?
Anhydrous copper(II) sulfate can be made by heating hydrated copper(II) sulfate.
$\text{CuSO}_4·5\text{H}_2\text{O} \rightarrow \text{CuSO}_4 + 5\text{H}_2\text{O}$
What can be added to anhydrous copper(II) sulfate to turn it into hydrated copper(II) sulfate?
Which fuel does not produce carbon dioxide when it burns?
A student investigates the rate of reaction between zinc and an excess of sulfuric acid. The graph shows the results of two experiments, X and Y.
Which change explains the difference between X and Y?
Which are properties of an acid?
1. reacts with ammonium sulfate to form ammonia
2. turns red litmus blue
[Table_1]
Which of the following are properties of the oxides of non-metals?
[Table_1]
The reactions shown may occur in the air during a thunder storm.
$$N_2 + O_2 \rightarrow 2NO$$
$$2NO + O_2 \rightarrow 2NO_2$$
$$NO + O_3 \rightarrow NO_2 + O_2$$
Which row shows what happens to the reactant molecules in each of these reactions?
[Table_1]
Calcium, on the left of Period 4 of the Periodic Table, is more metallic than bromine on the right of this period.
Why is this?
Calcium has
Compound X is tested and the results are shown in the table.
[Table_1]
Which ions are present in compound X?
Some properties of four elements W, X, Y, and Z are listed.
1. W melts at 1410 °C and forms an acidic oxide.
2. X has a high density and is easily drawn into wires.
3. Y acts as a catalyst and its oxide reacts with acids.
4. Z is a red-brown solid used to make alloys.
Which of the elements are metals?
The diagram shows a light bulb.
Why is argon used instead of air in the light bulb?
An element has a melting point of 1084°C and a density of 8.93 g/cm³. Its oxide can be used as a catalyst.
In which position in the Periodic Table is the element found?
The diagrams show the labels of four bottles. Which label is not correct?
Equations P and Q represent two reactions which occur inside a blast furnace.
P \[ \text{ } \text{ } \text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow 2\text{Fe} + 3\text{CO}_2 \]
Q \[ \text{ } \text{ } \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
Which type of reactions are P and Q?
[Table_1]
Farmers add calcium oxide (lime) and ammonium salts to their fields. The compounds are not added at the same time because they react with each other. Which gas is produced in this reaction?
Which row describes the uses of mild steel and stainless steel? [Table_1]
Reactions of three metals and their oxides are listed in the table.
[Table_1]
What is the order of reactivity of the metals?
The diagrams show four uses of iron.
In which of these uses is the iron most likely to rust?
In which process is carbon dioxide not formed?
M is a shiny silver metal. It has a melting point of 1455°C. Many of its compounds are green.
What is metal M?
In many countries river water is used for the washing of clothes.
The same water is not considered to be safe for drinking.
Why is it not safe for drinking?
The diagram shows a kiln used to heat limestone.
What is the product and what waste gas is formed?
Which air pollutant is not made when coal burns in a power station?
The diagram shows some properties of two organic compounds X and Y.
What are X and Y?
Three types of organic compound are alkanes, alkenes and alcohols. Which structure does not belong to any of these three types of compound?
The diagram represents ethene.
Which compound has chemical properties similar to those of ethene?
Petroleum is a mixture of hydrocarbons which can be separated into fractions using fractional distillation.
Which fraction is used as fuel in jet engines?
A chemist carried out a cracking reaction on a hydrocarbon, X, and obtained two products, Y and Z.
The chemist then wrote the following statements in his notebook.
1 A molecule of X has 7 carbon atoms.
2 Y is unsaturated.
3 Z will decolourise bromine water.
Which statements are correct?