Cambridge IGCSE Chemistry - 0620 - Supplement Paper 2 2009 Winter Zone 2

A student separates salt from a mixture of salt and sand. What is the correct order of steps for the student to take?
A filter → evaporate → shake with water
B filter → shake with water → evaporate
C shake with water → evaporate → filter
D shake with water → filter → evaporate

Aqueous lead(II) nitrate and aqueous potassium iodide are added to a dish containing water, as shown.
[Image_1: Diagram of two droppers adding solutions to a dish]
A yellow precipitate forms after a few minutes.
Which process occurs before the precipitate forms?
A diffusion
B distillation
C fermentation
D filtration

A student carries out an experiment to prepare pure magnesium sulfate crystals. The diagram shows the first stage of the preparation. He adds magnesium carbonate until no more reacts. Which process should he use for the next stage?
A. crystallisation
B. evaporation
C. filtration
D. neutralisation

Which change to an atom occurs when it forms a positive ion?
A. It gains electrons.
B. It gains protons.
C. It loses electrons.
D. It loses protons.

Statements 1, 2 and 3 are about diamond and graphite.
1. They are different solid forms of the same element.
2. They each conduct electricity.
3. They have atoms that form four equally strong bonds.
Which statements are correct?
A. 1 only B. 3 only C. 1 and 3 D. 2 and 3

Covalent bonds are formed when electrons are ......1...... . Covalent compounds have ......2...... electrical conductivity.
Which words correctly complete gaps 1 and 2?

[Table_1]
1       2
A   shared  high
B   shared  low
C   transferred  high
D   transferred  low

Atom X has 8 more electrons than atom Y.
Student 1 says they are in the same group.
Student 2 says they are unreactive.
Which students can be correct?

[Table_1]

Which number is different for isotopes of the same element?
A number of electrons
B number of full shells
C number of nucleons
D number of protons

Which atom has two more electrons than an atom of a noble gas?
A alumnium
B bromine
C calcium
D rubidium

For each atom of carbon present in a molecule, there is an equal number of atoms of oxygen but twice as many atoms of hydrogen.
What is the formula of the molecule?
A C_2H_2O_2
B C_2H_2O_4
C C_2H_4O_2
D C_2H_6O

Water is formed when 48 g of oxygen combine with 6 g of hydrogen.
What mass of oxygen combines with 2 g of hydrogen?

A. 12 g
B. 16 g
C. 96 g
D. 144 g

The diagram shows an electrical cable.

Which statement about the substances used is correct?
A. The coating is plastic because it conducts electricity well.
B. The core is copper because it conducts electricity well.
C. The core is copper because it is cheap and strong.
D. The core is iron because it is cheap and strong.

The diagram shows how aluminium is manufactured by electrolysis.
[Image_1: Diagram of electrolysis showing anode (+ve), cathode (−ve), aluminium oxide dissolved in cryolite, molten aluminium]
What are the anode and cathode made of?

| | anode | cathode |
|---------|---------------|---------------|
| A | aluminium | aluminium |
| B | aluminium | graphite |
| C | graphite | aluminium |
| D | graphite | graphite |

The diagram shows the electrolysis of concentrated aqueous sodium chloride.
What is the colour of the Universal Indicator at each electrode after five minutes?
[Table_1]
A. blue/purple, red
B. red, blue/purple
C. red, colourless
D. colourless, blue/purple

When an acid is added to an alkali the temperature rises. Which words describe this reaction?
A decomposition and endothermic
B decomposition and exothermic
C neutralisation and endothermic
D neutralisation and exothermic

Substance X requires oxygen in order to produce energy.
It does \textbf{not} form carbon dioxide as a result of this energy production.
What is substance X?
A) hydrogen
B) natural gas
C) petrol
D) $^{235}\text{U}$

Which change does not increase the speed of reaction between zinc and hydrochloric acid?
A. adding a catalyst
B. decreasing the temperature
C. decreasing the particle size of the zinc
D. using more concentrated acid

When blue copper(II) sulfate is heated, a white solid and water are formed.
The white solid turns blue and gives out heat when water is added to it.
Which terms describe the blue copper(II) sulfate and the reactions?

[Table_1]

the blue
copper(II) sulfate is | reaction
----------------------------------
A | a mixture | can be reversed
B | a mixture | cannot be reversed
C | hydrated | can be reversed
D | hydrated | cannot be reversed

The equations represent redox reactions.
In which equation is the underlined substance acting as a reducing agent?
\( A \) \( \underline{\text{CaO}} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 \)
\( B \) \( \underline{\text{CO}_2} + \text{C} \rightarrow 2\text{CO} \)
\( C \) \( \underline{\text{CuO}} + \text{H}_2 \rightarrow \text{Cu} + \text{H}_2\text{O} \)
\( D \) \( 3\underline{\text{CO}} + \text{Fe}_2\text{O}_3 \rightarrow 2\text{Fe} + 3\text{CO}_2 \)

An aqueous solution Y contains both barium ions and silver ions.
In separate experiments, dilute sulfuric acid and dilute hydrochloric acid are added to solution Y.
Which of these acids causes a precipitate to form in solution Y?

[Table_1]

The diagram shows the pH values of four solutions.

Which of these solutions are alkaline?
A P only
B P and Q only
C Q, R and S only
D R and S only

Salts can be prepared by reacting a dilute acid
1 with a metal;
2 with a base;
3 with a carbonate.
Which methods could be used to prepare copper(II) chloride?
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3

The diagram shows the position of an element X in the Periodic Table. [Image_1: Periodic Table Diagram with X]
What is the correct classification of element X and its oxide?
[Table_1: Classification Options]
\begin{array}{cc} X & \text{oxide of } X \\ \hline \textbf{A} & \text{metal} & \text{acidic} \\ \textbf{B} & \text{metal} & \text{basic} \\ \textbf{C} & \text{non-metal} & \text{acidic} \\ \textbf{D} & \text{non-metal} & \text{basic} \\ \end{array}

Elements in Group 0 of the Periodic Table have uses.
These noble gases are ……1…… and this explains why argon ……2…… be used in lamps.
Which words correctly complete gaps 1 and 2?

Astatine is an element in Group VII of the Periodic Table. It has only ever been produced in very small amounts.
What is the best description of its likely properties?

[Table_1]

| | colour | state | reaction with aqueous potassium iodide | |---|------------|-------|--------------------------------------| | A | black | solid | no reaction | | B | dark brown | gas | brown colour | | C | green | solid | no reaction | | D | yellow | liquid| brown colour |

Which property do all metals have?
A. They are soluble in water.
B. They conduct electricity.
C. They have high melting points.
D. They react with dilute sulfuric acid.

The table gives information about four elements. Which element is a transition metal?

[Table_1]

colour of element | electrical conductivity of element | colour of oxide
A | black | high | colourless
B | colourless | low | white
C | grey | high | red
D | yellow | low | colourless

Some reactions of three metals are listed in the table.

What is the order of reactivity of the metals?

Which object is least likely to contain aluminium?
A a bicycle frame
B a hammer
C a saucepan
D an aeroplane body

Which statement about alloys is \textit{not} correct?
A: Alloys are more expensive than the metals they are made from.
B: Alloys are mixtures of different metals.
C: Alloys are not as strong as the metals they are made from.
D: Alloys conduct electricity well.

Compound X is heated with carbon using the apparatus shown.
A brown solid is formed in the reaction tube and the limewater turns cloudy.
What is compound X?
A calcium oxide
B copper(II) oxide
C magnesium oxide
D sodium oxide

Water must be purified before it is suitable for use in the home.
Which processes are used to remove solid impurities and bacteria?
[Table_1]

[Table_1]

A newspaper article claims that carbon dioxide is formed as follows.
1 during respiration
2 when calcium carbonate reacts with hydrochloric acid
3 when methane burns in air
Which statements are correct?
A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only

Which iron nail rusts?

[Image_1: Diagram showing four situations: A - zinc coated nail, B - painted nail, C - nail in damp cloth, D - nail covered in grease]

Fertilisers are used to provide three of the elements needed for plant growth. Which two compounds would give a fertiliser containing all three of these elements?
A. Ca(NO₃)₂ and (NH₄)₂SO₄
B. Ca(NO₃)₂ and (NH₄)₃PO₄
C. KNO₃ and (NH₄)₂SO₄
D. KNO₃ and (NH₄)₃PO₄

A new planet has been discovered and its atmosphere has been analysed.
The table shows the composition of the atmosphere.
[Table_1]
Which gases are present in the atmosphere of the planet in a higher percentage than they are in the Earth's atmosphere?
A carbon dioxide and oxygen
B carbon dioxide only
C nitrogen and oxygen
D nitrogen only

Butene and hexene belong to the same homologous series.
What is the same for butene and hexene?
A boiling point
B functional group
C number of hydrogen atoms per molecule
D relative molecular mass

Which statement about petroleum is not correct?

A It can be separated into useful substances by fractional distillation.
B It consists mainly of hydrocarbons.
C It is found underground in many parts of the world.
D Its main use is for making lubricants and polishes.

The apparatus shows an experiment used to test gas X.
The bromine solution quickly becomes colourless. What is the structure of gas X?
A. [Image_A] B. [Image_B] C. [Image_C] D. [Image_D]

The table shows the formulae of members of the alkane series.

[Table_1]

What is the formula of propane?
A $\text{C}_2\text{H}_8$
B $\text{C}_3\text{H}_7$
C $\text{C}_3\text{H}_8$
D $\text{C}_3\text{H}_9$