A Level Chemistry all Paper 1 Questions and Answers – 100% Solved
0 1 . 3 The enthalpy of lattice formation for caesium iodide in Table 1 is a value obtained by
experiment. The value obtained by calculation using the perfect ionic model is -582 kJmol-1
Deduce what these values indicate about the bonding in caesium iodide.
(Enthalpy of lattice formation of caesium iodide -585)
[1 mark] - ✔✔✔-almost perfectly ionic
0 1 . 4 Magnesium chloride dissolves in water. Give an equation, including state symbols, to
represent the process that occurs when the enthalpy of solution of magnesium chloride is
measured. [1 mark] - ✔✔✔-MgCl2(s) → Mg2+(aq) + 2 Cl ‒ (aq)
0 1 . 4 Table 3 shows enthalpy of hydration values for ions of some Group 1 elements.
enthalpy of hydration: Li+= -519, Na+= -406, K+= -322
Explain why the enthalpy of hydration becomes less exothermic from Li+ to K+ [2 marks] -
✔✔✔-size increases/ charge density decreases
electrostatic attraction between metal ion and O- of water
0 1 . 4 Use data from Table 2 to show that this reaction is not feasible at 298
CsI(s) --> C2(s) + 1/2I2(s) ∆H= +337
∆S:
CsI= 130
Cs= 82.8
I2= 117
[4 marks] - ✔✔✔-1) find ∆S:
141.3 - 130= 11.3
2) find ∆G:
∆G= ∆H - T∆S
∆G= 337 - ( 298 x 0.0113) = 334
,A Level Chemistry all Paper 1 Questions and Answers – 100% Solved
0 1 . 5 Table 2 shows some enthalpy data.
enthalpy of lattice dissociation of MgCl2= +2493
enthalpy o f hydration of Mg2+= -1920
enthalpy of hydration of Cl-= -364
Use your answer to Question 01.4 and the data in Table 2 to calculate a value for the enthalpy
of solution of magnesium chloride. [2 marks] - ✔✔✔--2493 +(-1920 + -728)= 155
= -155
0 2 . 2 A sample of chromium containing the isotopes 50Cr, 52Cr and 53Cr has a relative atomic
mass of 52.1 The sample contains 86.1% of the 52Cr isotope. Calculate the percentage
abundance of each of the other two isotopes. [4 marks] - ✔✔✔-1) create an algebraic equation:
52.1= (52 x 86.1) + (50x) + (53x [13.9 - x])/100
2) rearrange for x:
5210= 4477.2 + 50x + 736.7 - 53x
5210= 5213.9 + -3x
-3x = -3.9
x= 1.3
3) find the abundances:
13.9- 1.3 = 12.6
so abundances are 53= 12.6% and 50= 1.3%
0 2 . 2 What is the relative molecular mass of P?
555, 556 or 557? [1 mark] - ✔✔✔-555
0 2 . 3 State, in terms of the numbers of fundamental particles, one similarity and one
difference between atoms of 50Cr and 53Cr [2 marks] - ✔✔✔-same number of electrons
, A Level Chemistry all Paper 1 Questions and Answers – 100% Solved
different number of neutrons
0 2 . 4 Give two reasons why it is necessary to ionise the isotopes of chromium before they can
be analysed in a TOF mass spectrometer.
[2 marks] - ✔✔✔-ions can be accelerated by an electric field
ions create a current when hitting the detector
0 2 . 5 A 53Cr+ ion travels along a flight tube of length 1.25 m
The ion has a constant kinetic energy (KE) of 1.102 × 10-13 J
KE = mv^2/2
m = mass of the ion / kg
v = speed of ion / m s-1 Calculate the time, in s, for the 53Cr+ ion to travel down the flight tube
to reach the detector.
The Avogadro constant, L = 6.022 × 1023 mol-1
[5 marks] - ✔✔✔-1) rearrange:
V= √2KE/m
2) find the mass of the ion:
(53/6.022x10^23)/1000= 8.801x10-26
3) substitute:
V= √2 x 1.102x10^-13/ 8.801x10^-26= 1582480.3
4) find the time:
t= d/v= 1.25/1582480.3= 7.9x10-7
0 2 . 5 A 53Cr+ ion travels along a flight tube of length 1.25 m The ion has a constant kinetic
energy (KE) of 1.102 × 10-13 J 2
KE = mv2/2
m = mass of the ion / kg
0 1 . 3 The enthalpy of lattice formation for caesium iodide in Table 1 is a value obtained by
experiment. The value obtained by calculation using the perfect ionic model is -582 kJmol-1
Deduce what these values indicate about the bonding in caesium iodide.
(Enthalpy of lattice formation of caesium iodide -585)
[1 mark] - ✔✔✔-almost perfectly ionic
0 1 . 4 Magnesium chloride dissolves in water. Give an equation, including state symbols, to
represent the process that occurs when the enthalpy of solution of magnesium chloride is
measured. [1 mark] - ✔✔✔-MgCl2(s) → Mg2+(aq) + 2 Cl ‒ (aq)
0 1 . 4 Table 3 shows enthalpy of hydration values for ions of some Group 1 elements.
enthalpy of hydration: Li+= -519, Na+= -406, K+= -322
Explain why the enthalpy of hydration becomes less exothermic from Li+ to K+ [2 marks] -
✔✔✔-size increases/ charge density decreases
electrostatic attraction between metal ion and O- of water
0 1 . 4 Use data from Table 2 to show that this reaction is not feasible at 298
CsI(s) --> C2(s) + 1/2I2(s) ∆H= +337
∆S:
CsI= 130
Cs= 82.8
I2= 117
[4 marks] - ✔✔✔-1) find ∆S:
141.3 - 130= 11.3
2) find ∆G:
∆G= ∆H - T∆S
∆G= 337 - ( 298 x 0.0113) = 334
,A Level Chemistry all Paper 1 Questions and Answers – 100% Solved
0 1 . 5 Table 2 shows some enthalpy data.
enthalpy of lattice dissociation of MgCl2= +2493
enthalpy o f hydration of Mg2+= -1920
enthalpy of hydration of Cl-= -364
Use your answer to Question 01.4 and the data in Table 2 to calculate a value for the enthalpy
of solution of magnesium chloride. [2 marks] - ✔✔✔--2493 +(-1920 + -728)= 155
= -155
0 2 . 2 A sample of chromium containing the isotopes 50Cr, 52Cr and 53Cr has a relative atomic
mass of 52.1 The sample contains 86.1% of the 52Cr isotope. Calculate the percentage
abundance of each of the other two isotopes. [4 marks] - ✔✔✔-1) create an algebraic equation:
52.1= (52 x 86.1) + (50x) + (53x [13.9 - x])/100
2) rearrange for x:
5210= 4477.2 + 50x + 736.7 - 53x
5210= 5213.9 + -3x
-3x = -3.9
x= 1.3
3) find the abundances:
13.9- 1.3 = 12.6
so abundances are 53= 12.6% and 50= 1.3%
0 2 . 2 What is the relative molecular mass of P?
555, 556 or 557? [1 mark] - ✔✔✔-555
0 2 . 3 State, in terms of the numbers of fundamental particles, one similarity and one
difference between atoms of 50Cr and 53Cr [2 marks] - ✔✔✔-same number of electrons
, A Level Chemistry all Paper 1 Questions and Answers – 100% Solved
different number of neutrons
0 2 . 4 Give two reasons why it is necessary to ionise the isotopes of chromium before they can
be analysed in a TOF mass spectrometer.
[2 marks] - ✔✔✔-ions can be accelerated by an electric field
ions create a current when hitting the detector
0 2 . 5 A 53Cr+ ion travels along a flight tube of length 1.25 m
The ion has a constant kinetic energy (KE) of 1.102 × 10-13 J
KE = mv^2/2
m = mass of the ion / kg
v = speed of ion / m s-1 Calculate the time, in s, for the 53Cr+ ion to travel down the flight tube
to reach the detector.
The Avogadro constant, L = 6.022 × 1023 mol-1
[5 marks] - ✔✔✔-1) rearrange:
V= √2KE/m
2) find the mass of the ion:
(53/6.022x10^23)/1000= 8.801x10-26
3) substitute:
V= √2 x 1.102x10^-13/ 8.801x10^-26= 1582480.3
4) find the time:
t= d/v= 1.25/1582480.3= 7.9x10-7
0 2 . 5 A 53Cr+ ion travels along a flight tube of length 1.25 m The ion has a constant kinetic
energy (KE) of 1.102 × 10-13 J 2
KE = mv2/2
m = mass of the ion / kg
