Q1.
Hydrogen chloride (HCl) can be made by the reaction of hydrogen (H2) with chlorine
(Cl2).
(a)
The diagrams represent molecules of hydrogen and chlorine.
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.
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(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.
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(1)
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(d)
Why does magnesium chloride have a much higher melting point than hydrogen
chloride?
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(2)
(Total 6 marks)
Q2.
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)
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(b)
Name the type of bonding which holds the nitrogen and hydrogen atoms together in
an ammonia molecule.
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(1)
(Total 2 marks)
Q3.
(a)
A piece of lithium is placed on the surface of some water in a beaker.
Hydrogen is given off.
Lithium hydroxide is also formed.
Write a word equation for this reaction.
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(2)
(b)
The diagram shows the structure of a molecule of methane.
Write down everything that this diagram tells you about a methane molecule.
To gain full marks in this question you should write your ideas in good English. Put
them into a sensible order and use the correct scientific words.
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(4)
(Total 6 marks)
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Q4.
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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(Total 4 marks)
Q5.
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)
(ii)
the compound sodium chloride.
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(4)
(Total 7 marks)
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M1.
(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
+
Cl2
→
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
(d)
1
because magnesium chloride is made of ions or is ionic
accept there are strong forces of attraction between the ions
/ particles in MgCl2 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
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do not accept reference to breaking bonds
do not accept MgCl2 is a solid and HCl is a gas
1
[6]
M2.
(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]
M3.
(a)
LHS lithium + water
accept Li and H2O
accept hydrogen oxide for water
1
RHS hydrogen + lithium hydroxide
accept H2 and LiOH
ignore attempts at balancing
ignore charges
1
(b)
Quality of written communication
One mark for the correct use of any
three of the terms atom, covalent,
bond(ing), saturated, hydrocarbon
or alkane
1
any three from:
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one / the carbon (atom)
reject molecules once
four hydrogen (atoms)
shape / properties neutral
CH4
hydrocarbon
saturated / single bond
covalent bond / shared electrons
alkane
reject ionic bond
3
[6]
M4.
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
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1
[4]
M5.
(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
(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]
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