Ca2+(aq) + 2Br–(aq)
Enthalpy change Value / kJ mol–1
enthalpy change of solution of CaBr –73
Question
Mathematics
Edexcel2021
enthalpy change of hydration of Ca2+ –1577
enthalpy change of hydration of Br– –336
Calculate the lattice energy of calcium bromide.
(2)
(Total for Question 9 = 12 marks)
Question
Mathematics
Edexcel2021
*P65463A0228*
PPMMTT
Answer ALL questions.
Some questions must be answered with a cross in a box .
If you change your mind about an answer, put a line through the box
and then mark your new answer with a cross .
Question
Mathematics
Edexcel2021
Barium ions can be identified by their flame colour.
(a) Which of the following should be used for a flame test on barium carbonate?
(1)
A iron wire and water
B iron wire and concentrated hydrochloric acid
C nichrome wire and water
D nichrome wire and concentrated hydrochloric acid
(b) What colour do barium ions give in a flame test?
(1)
A green
B lilac
C red
D yellow
(c) A flame test was carried out on a mixture of barium chloride and magnesium chloride.
How does the presence of magnesium ions affect the appearance of the flame colour
of barium ions?
(1)
A the colour is more intense
B a bright white colour completely masks the barium colour
C there is no change
D the barium colour is decreased by the white magnesium flame colour
(Total for Question 2 = 3 marks)
Question
Mathematics
Edexcel2021
2
(2)
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(ii) A different bleaching agent can be made by the reaction of chlorine with
sodium hydroxide under different conditions.
Balance this equation.
NaOH + Cl → NaClO + NaCl + H O
............ ............ 2 3 ............ ............ 2
(1)
(iii) What conditions are required for the reaction in (b)(ii)?
(1)
A cold and dilute alkali
B cold and concentrated alkali
C hot alkali
D excess chlorine
Question
Mathematics
Edexcel2021
4 5
(3)
Question
Mathematics
Edexcel2021
2 4 2 3 2
(i) Give two reasons why you would expect ΔSd to be positive.
system
(2)
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(ii) Explain why the wooden block is lifted up by the flask.
(2)
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Question
Mathematics
Edexcel2021
Substance Standard molar entropy, Sd / J K–1 mol–1
Mg(s) 32.7
O (g) 205.0
Question
Mathematics
Edexcel2021
MgO(s) 26.9
(1)
A +210.8
B –210.8
C +216.6
D –216.6
(Total for Question 6 = 5 marks)
x y
In an experiment, 0.10 mol of a complex reacted with excess silver nitrate solution
to produce 0.20 mol of silver chloride.
Chloride ions which are ligands within the complex do not react with
silver nitrate.
Deduce the formula of this chromium(III) complex ion. Justify your answer.
(2)
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(Total for Question 8 = 12 marks)