In which changes do the particles move further apart?
Gases are separated from liquid air by fractional distillation.
The boiling points of four gases are shown.
Which gas is both monoatomic and a liquid at –200 °C?
Impurities change the melting and boiling points of substances.
Sodium chloride is added to a sample of pure water.
How does the addition of sodium chloride affect the melting point and the boiling point of the water?
The apparatus used to separate a mixture of sand, methanol and ethanol is shown.
Which row identifies the labels on the diagrams?
A neutral atom, J, contains 45 neutrons and 35 electrons.
Which row is correct for atom J?
Lithium and fluorine react to form lithium fluoride.
A student writes three statements about the reaction.
1 Lithium atoms lose an electron when they react.
2 Each fluoride ion has one more electron than a fluorine atom.
3 Lithium fluoride is a mixture of elements.
Which statements are correct?
Which definition of isotopes is correct?
In which molecule are all the outer shell electrons from each atom used to form covalent bonds?
What is the balanced chemical equation for the reaction between calcium and water?
A compound has the formula XF₂ and has a relative mass of 70.
What is element X?
The diagram shows a section of an overhead power cable.
Which statement explains why a particular substance is used?
Three substances are electrolysed using inert electrodes.
Which substances produce hydrogen at the negative electrode?
1 concentrated hydrochloric acid
2 concentrated aqueous sodium chloride
3 dilute sulfuric acid
Which row describes an endothermic reaction?
Fuels release heat energy when they burn.
Which substances are used as fuels?
1 argon
2 butane
3 hydrogen
4 methane
When zinc carbonate is mixed with dilute hydrochloric acid a change, M, takes place.
When carbon is heated with copper(II) oxide a change, N, takes place.
Which row describes changes M and N?
The apparatus shown is used to measure the rate of a reaction.
Which equation represents a reaction where the rate can be measured using this apparatus?
P is a hydrated metal salt with a blue colour. When P is heated, water is given off, leaving solid Q.
R is a hydrated metal salt with a pink colour. When R is heated, water is given off, leaving solid S.
Which row gives the name of P and the colour of S?
Which property is shown by the alkali sodium hydroxide?
Part of the Periodic Table is shown.
Which element forms an acidic oxide?
When aqueous sodium hydroxide is added to a solution of a metal ion, a grey-green precipitate forms, which dissolves in excess to form a dark green solution.
What is the identity of the metal ion?
Which statements describe the Periodic Table?
1 The elements are arranged in order of their nucleon number.
2 The elements are arranged in order of their proton number.
3 It is used to predict the properties of elements.
Which row shows how the properties of the Group I elements change on descending the group?
Copper is a transition element.
Two compounds of copper are copper(II) oxide and copper(II) carbonate.
Which row describes the two compounds?
The metal beryllium does not react with cold water.
It reacts with hydrochloric acid but cannot be extracted from its ore by using carbon.
Where is beryllium placed in the reactivity series?
Pure iron is a soft metal.
When mixed with small amounts of tungsten it produces a hard alloy called tungsten steel.
1 Pure iron is a transition element.
2 The particles in pure iron are arranged in ordered layers.
3 Tungsten steel is a compound.
Which row describes magnesium?
Four equations are shown.
Which equations represent reactions that take place during the extraction of iron from hematite?
Copper is used to make saucepans.
Which properties of copper make it suitable for this use?
1 Copper has a relatively high melting point.
2 Copper has a low density.
3 Copper is a good conductor of electricity.
4 Copper is a good conductor of heat.
Which pollutants are responsible for the erosion of buildings and statues?
1 carbon monoxide
2 oxides of nitrogen
3 sulfur dioxide
Which combination of chemical compounds can be used to produce the fertiliser shown?
X is produced when petrol burns completely in air.
What is X?
Which substance is used as a bleach in the manufacture of paper?
What is an industrial use of calcium carbonate?
Which product is formed when calcium carbonate undergoes thermal decomposition?
The pie chart represents the composition of natural gas.
Which sector represents methane?
Which fraction, obtained from petroleum, is used for jet fuel?
The formula of a hydrocarbon is
The equation for its complete combustion is shown.
What are the values of x and y?
Pentane is an alkane and pentene is an alkene.
What is observed when bromine water is added to a sample of each compound?
Molecule 1 undergoes a process to make molecule 2.
Which row describes the molecules and the process?
Which substance has long-chain molecules and is a constituent of food?