Solutions Manual For Descriptive Inorganic Chemistry 6th
Edition By Rayner-Canham, Geoff 9781464125577 ALL
Chapters .
Which one of the following statements is correct?
A The first ionisation energies of the elements in Period 3 show a general decrease from sodium to
chlorine.
B The electronegativities of Group 2 elements decrease from magnesium to barium.
C The strength of the intermolecular forces increases from hydrogen fluoride to hydrogen chloride.
D The ability of a halide ion to act as a reducing agent decreases from fluoride to iodide. - ANSWER: B
State the meaning of the term electronegativity. - ANSWER: (a) Ability (or power) of an atom to
attract electron density(or electrons or -ve charge) (1) in a covalent bond (1)
or shared pairIf remove an electron lose first mark
State and explain the trend in electronegativity values across Period 3 from sodium to chlorine. -
ANSWER: Trend: increases (1)Explanation: nuclear charge (number of protons) increases (1)electrons
in same shell (1)
OR similar shielding OR atoms similar size or smaller OR 1 mol of e-
What is meant by the term first ionisation energy? - ANSWER: Heat / enthalpy / energy for removal of
one electron (1)from a gaseous atom (1)can score in an equation
must have first mark to score the second
Oxide P is a solid with a high melting point. It does not conduct electricity when solid but does
conduct when molten or when dissolved in water. Oxide P reacts with water forming a solution with a
high pH.
Oxide Q is a colourless gas at room temperature. It dissolves in water to give a solution with a low pH.
(i) Identify P. State the type of bonding present in P and explain its electrical conductivity. Write an
equation for the reaction of P with water. - ANSWER: (a) (i) Deductions:
Ionic (1) Ions not free to move in the solid state (1) Ions free to move when molten or in aqueous
solution (1) Identity of P: Na2O or sodium oxide (1)
N.B. If a formula given this must be correct
Equation: Na2O + H2O → 2 NaOH (1)
Identify Q. State the type of bonding present in Q and explain why it is a gas at room temperature.
Write an equation for the reaction of Q with water - ANSWER: Deductions:
Covalent
Intermolecular forces are weak or van der Waals forces,or dipole-dipole
N.B. Any answer including a reference to hydrogen bonding is incorrect
Identity of Q: SO2 or sulphur dioxide (1)
Equation: SO2 + H2O → H2 SO3(1)
NB Allow max one for SO3
R is a hydroxide of a Period 3 element. It is insoluble in water but dissolves in both aqueous sodium
hydroxide and aqueous sulphuric acid.
(i) Give the name used to describe this behaviour of the hydroxide. - ANSWER: Amphoteric
Write equations for the reactions occurring. - ANSWER: Equation with NaOH
Al(OH)3 + NaOH → NaAl(OH)4
OR Al(OH)3(H2O)3 + OH- → [Al(OH)4(H2O)2]- + H2OOR Al(OH)3 + OH- → [Al(OH)4]-
R identified as Al(OH)3 or Al(OH)3(H2O)3 (1)A balanced equation (1)
N.B. Allow equation with six co-ordinate Aluminium and up to six OH- ligandsN.B. Allow equation
mark if M(OH)3 given in a balanced equation
, Equation with H2SO4
2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O
OR Al(OH)3(H2O)3 + H+ → [Al(OH)2(H2O)4+ + H2O
NB Allow equations with six co-ordinate Aluminium and up to six H2O ligands NB Allow equation mark
if M(OH)3 given in a balanced equation
Correct Al species as product (1)A balanced equation (1)
Suggest why R is insoluble in water. - ANSWER: Large lattice energy
or strong covalent bonds
or ΔHsoln is very positive
or ΔG is positive
or sum of hydration energies less than covalent bond energies (1)
This question is about the elements in Period 3 of the Periodic Table.
(a) State the element in Period 3 that has the highest melting point.
Explain your answer. - ANSWER: Silicon / Si
If not silicon then CE =
covalent (bonds)
M3 dependent on correct M2
Strong or many of the (covalent) bonds need to be broken / needs a lot of energy to break the
(covalent) bonds
Ignore hard to break
State the element in Period 3 that has the highest first ionisation energy.
Explain your answer. - ANSWER: Argon / Ar
If not argon then CE = . But if Kr chosen, lose M1 and allow M2+M3
Large(st) number of protons / large(st) nuclear charge
Ignore smallest atomic radius
Same amount of shielding / same number of shells / same number of energy levels
Allow similar shielding
Suggest the element in Period 3 that has the highest electronegativity value - ANSWER: Chlorine / Cl
Not Cl2, Not CL, Not Cl2
Name the shape of CCl2 - ANSWER: Bent / v shape
Ignore non-linear, angular and triangular
Apply list principle
Write an equation to show the formation of one mole of ClF3 from its elements - ANSWER: 0.5Cl2 +
3/2F2 -> ClF3
Explain why certain elements in the Periodic Table are classified as p-block elements. Illustrate your
answer with an example of a p-block element and give its electronic configuration. - ANSWER: (a)
Elements in the p block have their outer electron(s) inp orbital(s) or levels or sub-shells (1)example of
element (1)correct electronic configuration (1)
An atom of element Z has two more protons and two more neutrons than an atom of 34S16 . Give the
symbol, including mass number and atomic number, for this atom of Z. - ANSWER: 18Ar18
Complete the electronic configurations for the sulphur atom, S, and the sulphide ion, S2-. - ANSWER:
S: 1s2 2s2 2p6 3s2 3p4 (1)
Allow upper case letters
S2-: 1s2 2s2 2p6 3s2 3p6 (1)
If use subscript penalise once
Edition By Rayner-Canham, Geoff 9781464125577 ALL
Chapters .
Which one of the following statements is correct?
A The first ionisation energies of the elements in Period 3 show a general decrease from sodium to
chlorine.
B The electronegativities of Group 2 elements decrease from magnesium to barium.
C The strength of the intermolecular forces increases from hydrogen fluoride to hydrogen chloride.
D The ability of a halide ion to act as a reducing agent decreases from fluoride to iodide. - ANSWER: B
State the meaning of the term electronegativity. - ANSWER: (a) Ability (or power) of an atom to
attract electron density(or electrons or -ve charge) (1) in a covalent bond (1)
or shared pairIf remove an electron lose first mark
State and explain the trend in electronegativity values across Period 3 from sodium to chlorine. -
ANSWER: Trend: increases (1)Explanation: nuclear charge (number of protons) increases (1)electrons
in same shell (1)
OR similar shielding OR atoms similar size or smaller OR 1 mol of e-
What is meant by the term first ionisation energy? - ANSWER: Heat / enthalpy / energy for removal of
one electron (1)from a gaseous atom (1)can score in an equation
must have first mark to score the second
Oxide P is a solid with a high melting point. It does not conduct electricity when solid but does
conduct when molten or when dissolved in water. Oxide P reacts with water forming a solution with a
high pH.
Oxide Q is a colourless gas at room temperature. It dissolves in water to give a solution with a low pH.
(i) Identify P. State the type of bonding present in P and explain its electrical conductivity. Write an
equation for the reaction of P with water. - ANSWER: (a) (i) Deductions:
Ionic (1) Ions not free to move in the solid state (1) Ions free to move when molten or in aqueous
solution (1) Identity of P: Na2O or sodium oxide (1)
N.B. If a formula given this must be correct
Equation: Na2O + H2O → 2 NaOH (1)
Identify Q. State the type of bonding present in Q and explain why it is a gas at room temperature.
Write an equation for the reaction of Q with water - ANSWER: Deductions:
Covalent
Intermolecular forces are weak or van der Waals forces,or dipole-dipole
N.B. Any answer including a reference to hydrogen bonding is incorrect
Identity of Q: SO2 or sulphur dioxide (1)
Equation: SO2 + H2O → H2 SO3(1)
NB Allow max one for SO3
R is a hydroxide of a Period 3 element. It is insoluble in water but dissolves in both aqueous sodium
hydroxide and aqueous sulphuric acid.
(i) Give the name used to describe this behaviour of the hydroxide. - ANSWER: Amphoteric
Write equations for the reactions occurring. - ANSWER: Equation with NaOH
Al(OH)3 + NaOH → NaAl(OH)4
OR Al(OH)3(H2O)3 + OH- → [Al(OH)4(H2O)2]- + H2OOR Al(OH)3 + OH- → [Al(OH)4]-
R identified as Al(OH)3 or Al(OH)3(H2O)3 (1)A balanced equation (1)
N.B. Allow equation with six co-ordinate Aluminium and up to six OH- ligandsN.B. Allow equation
mark if M(OH)3 given in a balanced equation
, Equation with H2SO4
2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O
OR Al(OH)3(H2O)3 + H+ → [Al(OH)2(H2O)4+ + H2O
NB Allow equations with six co-ordinate Aluminium and up to six H2O ligands NB Allow equation mark
if M(OH)3 given in a balanced equation
Correct Al species as product (1)A balanced equation (1)
Suggest why R is insoluble in water. - ANSWER: Large lattice energy
or strong covalent bonds
or ΔHsoln is very positive
or ΔG is positive
or sum of hydration energies less than covalent bond energies (1)
This question is about the elements in Period 3 of the Periodic Table.
(a) State the element in Period 3 that has the highest melting point.
Explain your answer. - ANSWER: Silicon / Si
If not silicon then CE =
covalent (bonds)
M3 dependent on correct M2
Strong or many of the (covalent) bonds need to be broken / needs a lot of energy to break the
(covalent) bonds
Ignore hard to break
State the element in Period 3 that has the highest first ionisation energy.
Explain your answer. - ANSWER: Argon / Ar
If not argon then CE = . But if Kr chosen, lose M1 and allow M2+M3
Large(st) number of protons / large(st) nuclear charge
Ignore smallest atomic radius
Same amount of shielding / same number of shells / same number of energy levels
Allow similar shielding
Suggest the element in Period 3 that has the highest electronegativity value - ANSWER: Chlorine / Cl
Not Cl2, Not CL, Not Cl2
Name the shape of CCl2 - ANSWER: Bent / v shape
Ignore non-linear, angular and triangular
Apply list principle
Write an equation to show the formation of one mole of ClF3 from its elements - ANSWER: 0.5Cl2 +
3/2F2 -> ClF3
Explain why certain elements in the Periodic Table are classified as p-block elements. Illustrate your
answer with an example of a p-block element and give its electronic configuration. - ANSWER: (a)
Elements in the p block have their outer electron(s) inp orbital(s) or levels or sub-shells (1)example of
element (1)correct electronic configuration (1)
An atom of element Z has two more protons and two more neutrons than an atom of 34S16 . Give the
symbol, including mass number and atomic number, for this atom of Z. - ANSWER: 18Ar18
Complete the electronic configurations for the sulphur atom, S, and the sulphide ion, S2-. - ANSWER:
S: 1s2 2s2 2p6 3s2 3p4 (1)
Allow upper case letters
S2-: 1s2 2s2 2p6 3s2 3p6 (1)
If use subscript penalise once
