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Chenistry C2 question booklet part 1
94 minutes
94 marks
Page 1 of 34
Q1. The diagram represents a carbon atom.
(a) Use words from the box to answer the questions.
(i) What is the name of the central part of the atom?
............................................................................................................... (1)
electron neutron nucleus proton
(ii) What is the name of the particle with no charge?
............................................................................................................... (1)
(iii) What is the name of the particle with a negative charge?
............................................................................................................... (1)
(b) Use the diagram above to help you to answer these questions.
(i) Draw a ring around the atomic (proton) number of this carbon atom.
(1)
6 12 18
(ii) Draw a ring around the mass number of this carbon atom.
(1)
6 12 18
(c) A different carbon atom has 6 protons and 8 neutrons.
Draw a ring around the symbol that represents this atom.
(1)
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(d) The diagram shows the bonding in a methane molecule.
(i) Draw a ring around the chemical formula of a methane molecule.
(1)
CH4
CH4
C4H
(ii) Draw a ring around the word that describes methane.
(1)
compound element mixture
(iii) Draw a ring around the type of bonding in a methane molecule.
(1) (Total 9 marks)
covalent ionic metallic
Q2. The picture shows sodium reacting with chlorine. The reaction forms sodium chloride.
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(a) Use words from the box to answer the questions.
Which word best describes:
(i) sodium ....................................................................... (1)
(ii) sodium chloride? ........................................................ (1)
compound element hydrocarbon mixture
(b) When sodium reacts with chlorine the sodium atoms change into sodium ions.
The diagrams below represent a sodium atom and a sodium ion.
Use the diagrams to help you explain how a sodium atom turns into a sodium ion.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ (2)
(c) (i) The diagram below represents a chlorine atom.
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When chlorine reacts with sodium the chlorine forms negative chloride ions.
Complete the diagram below to show the outer electrons in a chloride ion (Cl–).
(1)
(ii) Chloride ions are strongly attracted to sodium ions in sodium chloride.
Explain why.
...............................................................................................................
............................................................................................................... (1)
(Total 6 marks)
Q3. The picture shows sodium reacting with chlorine.
The reaction forms sodium chloride, which contains sodium ions and chloride ions.
(a) The diagrams show how electrons are arranged in a sodium atom and a chlorine atom.
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Explain, in terms of electrons, what happens when sodium reacts with chlorine.
........................................................................................................................
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........................................................................................................................
........................................................................................................................
........................................................................................................................ (3)
(b) Explain, as fully as you can, why sodium chloride has a high melting point.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ (3)
(Total 6 marks)
Q4. This question is about oxygen atoms. The periodic table on the Data Sheet may help you to answer this question.
(a) (i) Oxygen atoms have 8 electrons.
Complete the diagram to represent the arrangement of electrons in an oxygen atom. Use crosses (×) to represent the electrons.
(1)
(ii) Name the part of the oxygen atom that is labelled A on the diagram.
........................................................................................................................... (1)
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(b) Two isotopes of oxygen are oxygen-16 and oxygen-18.
16 18
oxygen-16 oxygen-18
Explain, in terms of particles, how the nucleus of an oxygen-18 atom is different from the nucleus of an oxygen-16 atom.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(Total 4 marks)
Q5. Ammonia (NH3) is an important chemical which is used to make fertilisers. Ammonia is
made from nitrogen and hydrogen,
(a) The diagrams represent the electron arrangements in atoms of nitrogen and hydrogen.
Complete the diagram showing the arrangement of electrons in a molecule of ammonia.
(1)
O O8 8
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(b) Name the type of bonding which holds the nitrogen and hydrogen atoms together in an ammonia molecule.
..................................................................................................................................... (1)
(Total 2 marks)
Q6. Calcium and magnesium are elements. They are found in the Earth’s crust as compounds, often carbonates and sulphates. Magnesium is also found as its chloride.
(a) Calcium and magnesium are in the same Group in the Periodic Table. State which Group this is.
..................................................................................................................................... (1)
(b) Use the Data Sheet to help you to answer this question.
(i) Write the chemical formula of magnesium chloride.
........................................................................................................................... (1)
(ii) Name the type of bonding in magnesium chloride.
........................................................................................................................... (1)
(Total 3 marks)
Q7. Distress flares are used to attract attention in an emergency.
Flares often contain magnesium. Magnesium burns to form magnesium oxide.
(a) The distress flare burns with a bright flame because the reaction is very exothermic.
Complete the following sentence using the correct words from the box.
An exothermic reaction is one which .......................................................................... (1)
gives out heat stores heat takes in heat
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(b) The diagram shows the electronic structure of a magnesium atom. The atomic (proton) number of magnesium is 12.
Magnesium atom
The atomic (proton) number of oxygen is 8.
Which diagram, A, B, C or D, shows the electronic structure of an oxygen atom?
Diagram .............................. (1)
(c) Magnesium ions and oxide ions are formed when magnesium reacts with oxygen. The diagram shows the electronic structure of an oxide ion.
Oxide ion
Which diagram, J, K, L or M, shows the electronic structure of a magnesium ion?
Diagram .............................. (1)
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(d) Indigestion tablets can be made from magnesium oxide. The magnesium oxide neutralises some of the hydrochloric acid in the stomach.
Draw a ring around the name of the salt formed when magnesium oxide reacts with hydrochloric acid.
magnesium chloride magnesium hydroxide magnesium sulfate (1)
(Total 4 marks)
Q8. Metal is bent and shaped to make a car body.
The diagram below represents how atoms are arranged in a metal.
Which two statements in the table best explain why the metal can be bent and shaped?
Tick ( ) the two statements.
(2) (Total 2 marks)
Statement Tick ( )
The atoms are in layers.
The metal is shiny.
The atoms can slide over each other.
All the atoms are linked by strong covalent bonds.
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Q9. (a) Write a balanced symbol equation for the reaction between magnesium (Mg) and oxygen (O
2) to form magnesium oxide (MgO).
..................................................................................................................................... (1)
(b) The diagram shows the electronic structure of a magnesium atom. The atomic (proton) number of magnesium is 12.
Magnesium atom
Draw a similar diagram to show the electronic structure of an oxygen atom. The atomic (proton) number of oxygen is 8.
(1)
(c) Magnesium ions and oxide ions are formed when magnesium reacts with oxygen.
The diagram shows the electronic structure of an oxide ion.
Oxide ion
Draw a similar diagram to show the electronic structure of a magnesium ion.
(1)
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(d) Magnesium oxide is a white solid with a high melting point.
Explain how the ions are held together in solid magnesium oxide.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(e) Indigestion tablets can be made from magnesium oxide. The magnesium oxide neutralises some of the hydrochloric acid in the stomach.
Complete the word equation for the reaction between magnesium oxide and hydrochloric acid.
hydrochloric acid + magnesium oxide → ...................... + water. (1)
(Total 6 marks)
Q10. The diagram represents a particle of methane.
(a) What is the formula of methane? ............................................................................... (1)
(b) Choose a word from the box to answer the question.
Which of the words best describes the methane particle shown in the diagram?
................................................. (1)
atom ion molecule
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(c) Choose a word from the box to answer the question.
What is the type of bonding shown in the diagram?
.................................................. (1)
(Total 3 marks)
covalent ionic metallic
Q11. (a) The diagram represents an atom of nitrogen.
(i) Use words from the box to label the diagram.
(2)
electron neutron nucleus proton
(ii) Draw a ring around the mass number of this atom.
5 7 14 21 (1)
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(b) Nitrogen can react with hydrogen to make ammonia, NH3 .
Which diagram, A, B, C or D, best represents an ammonia molecule? (1)
(Total 4 marks)
Q12. This question is about sodium chloride (common salt) which is an important chemical.
Sodium chloride can be made by burning sodium in chlorine gas.
(a) Balance the symbol equation for the reaction of sodium with chlorine.
Na(s) + Cl2(g) → NaCl(s)
(1)
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(b) (i) Complete the diagrams below to show the electronic structures of a sodium and a chlorine atom. (Atomic number of sodium = 11 and chlorine = 17.)
(3)
(ii) When sodium reacts with chlorine the sodium atoms are changed into sodium ions (Na+) and the chlorine atoms are changed into chlorine ions (Cl–).
Explain how:
1. a sodium atom changes into a sodium ion;
...........................................................................................................................
........................................................................................................................... (2)
2. a chlorine atom changes into a chloride ion.
...........................................................................................................................
........................................................................................................................... (2)
(c) The element potassium is in the same group of the Periodic Table as sodium. Potassium reacts with chlorine to make potassium chloride which is sometimes used instead of common salt in cooking.
(i) Predict the formula of potassium chloride.
........................................................................................................................... (1)
By reference to the electronic structures of potassium and sodium explain:
(ii) Why the reaction of potassium with chlorine is similar to the reaction of sodium with chlorine.
...........................................................................................................................
........................................................................................................................... (1)
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(d) The electrolysis of sodium chloride solution is an important industrial process. The diagrams below show two experiments set up during an investigation of the electrolysis of sodium chloride.
(i) What would be the reading on the ammeter in experiment 1?
.................................................... A
(ii) Explain your answer.
...........................................................................................................................
...........................................................................................................................
........................................................................................................................... (3)
(e) The equations below show the reactions which take place in experiment 2.
H2O(1) → H +
(aq) + OH– (aq)
2H+(aq) + 2e– → H
2(g)
2Cl–(aq) – 2e– → Cl2(g)
(i) Which substance provides hydrogen ions?
........................................................................................................................... (1)
(ii) Name the product formed at:
(A) the positive electrode;
...........................................................................................................................
(B) the negative electrode.
........................................................................................................................... (1)
(Total 15 marks)
Page 16 of 34
Q13. (a) The electronic structure of a sodium atom can be written 2,8,1. Write the electronic structure of a potassium atom in the same way.
..................................................................................................................................... (1)
(b) The electronic structure of a sodium atom can also be represented as in the diagram below.
(i) Draw a similar diagram for a fluorine atom.
(ii) Draw similar diagrams to show the electronic structure of the particles in sodium fluoride.
(4)
(Total 5 marks)
Q14. Hydrogen chloride (HCl) can be made by the reaction of hydrogen (H2) with chlorine (Cl
2).
(a) The diagrams represent molecules of hydrogen and chlorine.
Page 17 of 34
Draw a similar diagram to represent a molecule of hydrogen chloride (HCl). You need show only the outer energy level (shell) electrons.
(1)
(b) The word equation for the reaction of hydrogen with chlorine is shown below.
hydrogen + chlorine → hydrogen chloride
Write a balanced symbol equation for this reaction.
..................................................................................................................................... (2)
(c) Hydrogen chloride gas reacts with magnesium to form the ionic compound called magnesium chloride. Use the table of ions on the Data Sheet to help you to write the formula of magnesium chloride.
..................................................................................................................................... (1)
(d) Why does magnesium chloride have a much higher melting point than hydrogen chloride?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(Total 6 marks)
Page 18 of 34
Q15. Millions of years ago the Earth formed as a giant ball of molten rock. The outer surface cooled forming a thin, solid outer crust. Volcanic activity on the surface produced an atmosphere containing the compounds carbon dioxide, ammonia, methane and water vapour.
Describe the bonding in any one of these compounds. You must include electronic structures in your explanation.
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...............................................................................................................................................
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............................................................................................................................................... (Total 4 marks)
Q16. Sodium reacts with chlorine to form the compound sodium chloride.
2Na + Cl2 → 2NaCl
Describe, in terms of electron arrangement, the type of bonding in:
(i) a molecule of chlorine;
....................................................................................................................................
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....................................................................................................................................
.................................................................................................................................... (3)
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(ii) the compound sodium chloride.
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....................................................................................................................................
.................................................................................................................................... (4)
(Total 7 marks)
Q17. Sodium chloride is a raw material.
(a) The electronic structure of a sodium atom is shown below.
Complete the diagram for the electronic structure of a chlorine atom. A chlorine atom has 17 electrons.
(1)
(b) When sodium and chlorine react to form sodium chloride they form sodium ions (Na+ ) and chloride ions (Cl– ).
How does a sodium atom change into a sodium ion?
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ (2)
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(c) The diagram shows apparatus used in a school laboratory for the electrolysis of sodium chloride solution.
The solution contains sodium ions (Na+), chloride ions (Cl– ), hydrogen ions (H + ) and hydroxide ions (OH– ).
(i) Why do chloride ions move to the positive electrode?
............................................................................................................... (1)
(ii) Name the gas formed at the negative electrode.
............................................................................................................... (1)
(d) Chlorine and chlorine compounds are used to bleach wood pulp that is used to make paper.
The article below is from a newspaper.
(i) Why are some local people worried about the use of chlorine compounds?
...............................................................................................................
............................................................................................................... (1)
Local people have been protesting outside a paper factory. They say: ‘We want the company to stop using chlorine compounds. Chlorine compounds release poisons into the environment. The company should use safer compounds.’
The company replied: ‘Chlorine has been used safely for many years to treat drinking water. Only tiny amounts of chlorine are released, which cause no harm. Using other compounds will be more expensive and may put us out of business.’
(ii) Why might other local people want the company to continue to use chlorine compounds?
...............................................................................................................
............................................................................................................... (1)
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(iii) It is decided to have an inquiry. Why should this be done by independent scientists?
...............................................................................................................
............................................................................................................... (1)
(Total 8 marks)
Page 22 of 34
M1. (a) (i) nucleus 1
(ii) neutron 1
(iii) electron 1
(b) (i) 6 1
(ii) 12 1
(c)
1
(d) (i) CH4
1
(ii) compound 1
(iii) covalent 1
[9]
M2. (a) (i) element 1
(ii) compound 1
(b) an / one electron from the sodium atom 1
is lost / transferred to form a sodium ion 1
(c) (i) 8 electrons drawn on outer energy level / shell 1
Page 23 of 34
(ii) because oppositely charged ions attract each other
or
because chloride ions are negative and sodium ions are positive 1
[6]
M3. (a) the sodium atom loses / transfers an / one electron 1
the chlorine atom gain(s) this / an / one electron 1
involves electrons in the outer energy levels / shells of both the sodium atom and the chlorine atom
1
(b) sodium chloride has a giant structure / lattice of oppositely charged ions / positive and negative ions
1
the electrostatic forces of attraction / bonds between ions are strong
1
therefore sodium chloride has a high melting point because a large amount of energy is needed to make the ions mobile
1 [6]
M4. (a) (i)
or 1
allow any arrangement of electrons on the shells accept o, x, - or e as representing electrons
(ii) nucleus accept nucleus (protons plus neutrons) do not accept protons plus neutrons on its own allow nuclei / nucles / neucleus / phonetic spelling do not accept neutron
1
Page 24 of 34
(b) it has 2 more neutrons or converse
accept ‘it has more neutrons’ or ‘different number of neutrons’ for 1 mark ‘2 more protons / electrons + correct number of neutrons’ = max 1 mark
or
O-16 has 8 neutrons (1 mark)(*)
O-18 has 10 neutrons (1 mark)(*)
(*)if incorrectly calculated but shows more neutrons in 0-18 allow for 1 mark accept it has more particles or it has 2 more particles for 1 mark ignore any reference to charges just 2 more without reference to particles = 0 marks
2 [4]
M5. (a) all electrons correct (inner shell need not be shown)
three bond pairs and two electrons anywhere else can use dots, crosses or e’s in any combination
1
(b) covalent accept phonetic spelling do not accept convalent
1 [2]
M6. (a) Group 2 / Alkaline Earth Metals
for 1 mark 1
(b) (i) MgCl2/Mg2+ (Cl–)
2
(or equation with correct answer) for 1 mark
1
(ii) ionic / electrovalent for 1 mark
1 [3]
Page 25 of 34
M7. (a) gives out (heat) 1
(b) D 1
(c) L 1
(d) magnesium chloride 1
[4]
M8. the atoms are in layers 1
the atoms can slide over each other 1
[2]
M9. (a) 2Mg + O2 → 2MgO
accept correct multiples / fractions 1
(b)
electrons do not need to be paired accept dots / circles / e instead of crosses do not allow 2.6 without diagram
1
Page 26 of 34
(c)
electrons do not need to be paired allow without bracket s/ must have the charge accept dots / circles / e instead of crosses ignore extra empty outer shells ignore nucleus
do not allow [2.8]2+ without diagram
1
(d) oppositely charged (ions / atoms) allow positive and negative(ions / atoms)
1
(they) attract must be in correct context accept held by electrostatic forces ignore ionic bonding maximum 1 if they refer to intermolecular forces / attractions / covalent bonds
1
(e) magnesium chloride accept MgCl
2 (if correctly written)
1 [6]
M10. (a) CH4
4 should be below halfway up H / tail of 4 below the dotted line 1
(b) molecule 1
(c) covalent 1
[3]
Page 27 of 34
M11. (a) (i)
all three correct 2 marks one correct 1 mark
2
(ii) 14 1
(b) A 1
[4]
M12. (a) 2 2 multiples of ½ allowed
for 1 mark 1
(b) (i) 2. 8. 1 and 2. 8. 7 gains 3 marks
1 mark for 2 electrons in each inner shell 1 mark for 8 electrons in each second shell 1 mark for 1 electron in sodium outer shell and 7 in chlorine outer shell
3
(ii) sodium atom loses; electron; chlorine atom gains; electron
for 1 mark each
inversion = 2 marks lose negative charge = 1 mark
4
(c) (i) KCl (accept 2KCl) for 1 mark
1
(ii) both have on electron in outer shell/same number of electrons/ lose same number of electrons in compound formation/ both lose one electron
for 1 mark 1
Page 28 of 34
(d) 0 amps; the ions; cannot move in the solid solid Na chloride does not conduct
for 1 mark each 3
(e) (i) water (H2O)
for 1 mark 1
(ii) (1) chlorine; (2) hydrogen
for 1 mark 1
[15]
M13. (a) 2, 8, 8, 1
for 1 mark 1
(b) for 1 mark
Ignore symbol in middle but structure must be drawn NOT 2,7
If covalent; can score mark for changes but not for diagram Arrow showing electron transfer from metal atom to non-metal atom = 2 marks If the ions are not identified then cannot score mark for changes
4 [5]
Page 29 of 34
M14. (a) bonding pair in the overlap and 6 other electrons arranged around the chlorine
must have either circles or symbols need not be pairs but must not be in the overlap region accept without H and Cl if clear accept all x’s or all o’s
1
(b) H2 + Cl
2 → 2HCl
accept multiples or fractions accept correct formulae but not balanced for 1 mark correctly balanced equation containing ‘correct’ lower / upper case symbols gets 1 mark
2
(c) MgCl2
accept Mg2+(Cl-)2
1
(d) because magnesium chloride is made of ions or is ionic
accept there are strong forces of attraction between the ions / particles in MgCl
2 or strong electrostatic attractions
accept more energy to separate particles in MgCl2
do not accept MgCl2 molecules
do not accept reference to breaking bonds 1
hydrogen chloride is made of molecules or is covalent
accept there are only weak forces of attraction (between the particles / molecules) in HCl do not accept weak covalent bonds do not accept reference to breaking bonds do not accept MgCl
2 is a solid and HCl is a gas
1 [6]
Page 30 of 34
M15. answers apply to:
accept diagrams and/or descriptions
carbon dioxide CO2
ammonia NH3
methane CH4
water H2O
*outer electronic structure of one atom correct or needs correct number of electrons to complete outer shell
1
*outer electronic structure of other atom correct or needs correct number of electrons to complete outer shell
1
*one shared pair of electrons (as one covalent bond)
use of ions or reference to ionic bonding negates this mark 1
*outer electronic structure of compound correct or each atom now has a full outer shell/noble gas electron structure
1 [4]
M16. (i) can be from diagram chlorine (2.8).7.
accept chlorine needs one more electron 1
can be from diagram shares a pair of electrons 1
shared pair of electrons is a covalent bond do not accept ionic bond
1
Page 31 of 34
(ii) can be from diagram and appropriately annotated sodium (2.8). 1. and chlorine (2.8).7
1
sodium loses one electron and chlorine gains one electron 1
Na+ and Cl– formed
1
bond formed between oppositely charged ions or ionic bond is formed
do not accept covalent bond 1
[7]
M17. (a)
accept dots / crosses / e must be drawn on diagram electrons do not need to be paired ignore brackets or + or -charges ignore 2,8,7
1
(b) (one) electron recognition that electrons are involved
1
lost / given away / transferred from sodium / transferred to chlorine owtte must be linked to electrons accept loses electron(s) for 2 marks NB loses 2 or more electrons gains 1 mark reference to sharing / covalent max 1 mark ignore charges on ions formed
1
(c) (i) any one from:
• ions / atoms / they are / it is negatively charged / anions accept they are negative
• opposite (charges) attract accept they are attracted or it is oppositely charged ignore opposite forces attract
1
Page 32 of 34
(ii) hydrogen accept H
2
ignore H or H+
1
(d) (i) poisons released into environment (owtte) accept any sensible idea of harm / harmful / poisons / poisonous / pollution / damaging do not accept answers such as global warming / ozone layer etc. ignore safety unless qualified
1
(ii) any one sensible idea eg
• loss of work / unemployment eg shops / house prices etc.
or company goes out of business
• any adverse effect on local economy (owtte)
• any adverse effect on paper production / cost of paper / cost of water (treatment) allow less expensive to use chlorine or converse
• chlorine (compounds) have been used (for many years) without causing harm owtte
• only a tiny amount of chlorine is released so it would not cause harm ignore uses of chlorine to treat drinking water unless qualified
1
(iii) ideas related to bias accept more reliable or valid or fair ignore more accurate / fair test
1 [8]
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