*P65463A0728*
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PPMMTT
(c) A sodium atom has 11 protons whereas a potassium atom has 19 protons.
Explain why the first ionisation energy of sodium is greater than that of potassium.
(3)
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Question
Mathematics
Edexcel2021
This question is about acids and buffer solutions.
(a) Ethanoic acid, CH COOH, is a monobasic acid.
Question
Mathematics
Edexcel2021
*P65463A02428*
PPMMTT
(b) Data for the Born-Haber cycle for copper(II) oxide are given in the table.
Label Energy change Value / kJ mol–1
A standard enthalpy change of atomisation of copper +338
B standard enthalpy change of atomisation of oxygen +249
C sum of first and second ionisation energies of copper +2704
D first electron affinity of oxygen –141
E second electron affinity of oxygen +798
F standard enthalpy change of formation of copper(II) oxide –157
(i) Complete the diagram of the Born-Haber cycle for copper(II) oxide.
Include labels of enthalpy changes with arrows indicating the direction of
change, and the respective species with state symbols.
(4)
Cu(s) + ½O (g)
Question
Mathematics
Edexcel2019
Sodium hydride, NaH, can be used to generate hydrogen for fuel cells.
(a) In order to calculate the first electron affinity of hydrogen, a student was asked to
draw a Born-Haber cycle for sodium hydride.
The cycle had two errors but the numerical data were correct.
Na+(g) + e– + H(g)
Half of the enthalpy change First electron affinity of hydrogen
of atomisation of hydrogen
+218 kJ mol–1
Na+(g) + H–(g)
Na+(g) + e– + ½H (g)
Question
Mathematics
Edexcel2019
Enthalpy change of formation
of sodium hydride –56 kJ mol–1
NaH(s)
(i) Identify and correct the two errors in this Born-Haber cycle.
(2)
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(ii) Calculate the first electron affinity, in kJ mol–1, of hydrogen, using the values
given in the cycle.
(1)
Question
Mathematics
Edexcel2018
*P52302RA01728*
Turn over
DO
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DO
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IN
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DO
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AERA
SIHT
NI
ETIRW
TON
OD
AERA
SIHT
NI
ETIRW
TON
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AERA
SIHT
NI
ETIRW
TON
OD
(b) The diagram, which is not drawn to scale, shows the Born-Haber cycle for
lithium fluoride. The energy changes are given in kJ mol−1.
Li+(g) + F(g) + e−
+79
Y
Li+(g) + ½F (g) + e−
Question
Mathematics
Edexcel2017
enthalpy change of formation of magnesium bromide, (cid:168)H [MgBr (s)] –524
f 2
(i) Complete the Born-Haber cycle for magnesium bromide with formulae,
electrons and labelled arrows. The cycle is not drawn to scale.
(3)
Mg(g) + Br (l)