Questions
Q1.
Salts and analysis
(a) Which of the following pairs of substances contains one substance that is soluble in water and one
that is insoluble in water?
Put a cross (
) in the box next to your answer.
(1)
A
B
C
D
aluminium nitrate and lead sulfate
ammonium chloride and copper sulfate
copper hydroxide and lead sulfate
sodium hydroxide and potassium nitrate
(b) Barium chloride is an ionic compound and has a high melting point.
Explain why barium chloride has a high melting point.
(2)
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(c) Barium chloride solution is used to test for the presence of sulfate ions in a solution.
When sulfate ions are present, insoluble barium sulfate is formed.
(i) Describe the appearance of barium sulfate.
(1)
.............................................................................................................................................
(ii) Complete the balanced equation for the reaction between barium chloride and potassium sulfate.
(2)
BaCl2 + K2SO4 → ................................................................................................
(d) Compound X is a metal carbonate.
(i) A flame test was carried out on compound X.
A lilac flame was seen.
Complete the sentence by putting a cross ( ) in the box next to your answer.
(1)
The formula of the metal ion in compound X is
A Ca2+
B Cu2+
C K+
D Na+
(ii) Lead carbonate is an insoluble salt.
Describe how a pure, dry sample of solid lead carbonate can be obtained from sodium carbonate
solution and lead nitrate solution.
(3)
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(Total for question = 10 marks)
Q2.
Explain the difference in the ability of solid sodium chloride and molten sodium chloride to conduct
electricity in terms of their structures.
(6)
Q3.
Sodium carbonate and copper chloride are both ionic solids.
They are both soluble in water.
(a) Which row of the table shows the most likely melting points of these two salts?
Put a cross (
) in the box next to your answer.
(1)
%%%
%%%
A
B
C
D
melting point / °C
sodium carbonate
17
851
851
9
copper chloride
498
9
498
17
Q4.
(a) The table shows the names and formulae of three ions.
name of ion
calcium
nitrate
phosphate
What is the formula of calcium nitrate?
Put a cross (
) in the box next to your answer.
formula of ion
Ca2+
NO3–
PO43–
(1)
A Ca2NO3
B CaNO3
C Ca3NO2
D Ca(NO3)2
(b) Complete the sentence by putting a cross (
) in the box next to your answer.
The number of oxygen atoms in the formula Ca3(PO4)2 is
(1)
A 2
B 4
C 8
D 12
(c) The table gives some information about the elements sodium and sulfur.
Sodium sulfide is an ionic compound.
Describe, in terms of electron transfer, how sodium atoms react with sulfur atoms to form sodium sulfide.
Your description should include the charges on the ions formed.
(4)
*(d) Explain the difference in the ability of solid sodium chloride and molten sodium chloride to conduct
electricity in terms
of their structures.
(6)
(Total for Question is 12 marks)
Mark Scheme
Q1.
Q2.
Indicative Content
*
Level
1
0
1-2
A description
including some of
the following points
solid
regular arrangement/
lattice (of ions)
sodium/Na+ ions
chloride /Cl- ions
(held together by)
strong (ionic) bonds
strong
(electrostatic) forces
of attraction
between oppositely
charged ions /
positive and
negatively
charged ions
closely packed
together
(when solid) does
not conduct
because ions
cannot move
molten
heat energy
overcomes/breaks
(strong ionic) bonds
strong (electrostatic)
forces of attraction
between oppositely
charged ions /
positive and
negatively
charged ions
ions can move
(therefore) conducts
when molten
No rewardable content
Mark
(6)
 a limited explanation e.g. does not
conduct when solid e.g. does conduct when
molten
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple explanation e.g. does not
conduct when solid, does conduct when
molten because ions / particles / atoms can
move
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed explanation e.g. solid has
strong ionic bonds (between oppositely
charged ions), does not conduct when solid
because ions cannot move, does conduct
when molten because ions can move
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors
Q3.
Answer
C
Acceptable
answers
Mark
(1)
Q4.
Answer
(a)
(b)
(c)
D : Ca(NO3)2
C:8
Description including
four of the following
sodium - 2.8.1 / 1
electron in outer
shell (1)
sodium (atoms) lose
electrons (1)
one per atom (1)
(forms) Na+ (1)
sulphur - 2.8.6 / 6
electrons in outer
shell (1)
sulfur (atoms) gain
electrons (1)
two per atom (1)
(forms) S2- (1)
two sodium atoms /
ions combine with
one sulfur atom / ion
(1)
formula is Na2S (1)
Acceptable
answers
Marks can be gained
using diagrams
mention of shared
electrons / covalent
bonding in words or
diagram = max 2
marks
Indicative Content
*(d)
A description
including some of
the following points
solid
regular arrangement/
lattice (of ions)
sodium/Na+ ions
chloride /Cl- ions
(held together by)
strong (ionic) bonds
strong
(electrostatic) forces
of attraction
between oppositely
charged ions /
positive and
negatively
charged ions
closely packed
together
(when solid) does
not conduct
because ions
cannot move
molten
heat energy
overcomes/breaks
(strong ionic) bonds
strong (electrostatic)
Mark
(1)
(1)
(4)
Mark
(6)
Level
1
0
1-2
forces of attraction
between oppositely
charged ions /
positive and
negatively
charged ions
ions can move
(therefore) conducts
when molten
No rewardable content
 a limited explanation e.g. does not
conduct when solid e.g. does conduct when
molten
 the answer communicates ideas using
simple language and uses limited scientific
terminology
 spelling, punctuation and grammar are
used with limited accuracy
2
3-4
 a simple explanation e.g. does not
conduct when solid, does conduct when
molten because ions / particles / atoms can
move
 the answer communicates ideas
showing some evidence of clarity and
organisation and uses scientific terminology
appropriately
 spelling, punctuation and grammar are
used with some accuracy
3
5-6
 a detailed explanation e.g. solid has
strong ionic bonds (between oppositely
charged ions), does not conduct when solid
because ions cannot move, does conduct
when molten because ions can move
 the answer communicates ideas clearly
and coherently uses a range of scientific
terminology accurately
 spelling, punctuation and grammar are
used with few errors