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Edexcel IAL Chemistry AS Topic 3 Bonding and structure

Edexcel IAL Chemistry AS Topic 3 Bonding and structure
Pearson Edexcel IAL Chemistry syllabusChemistry YCH11First assessment 2019

Identify the bonding and particles present, draw or interpret the requested representation and connect charge, geometry or intermolecular attraction to the observed property.

Exam points

  • Draw electron, ionic-lattice or molecular diagrams with correct charges and bonding.
  • Predict molecular shape and bond angle from electron-pair arrangement and repulsion.
  • Explain structure and properties through bonding, polarity and intermolecular forces.

Question 9

[Maximum number: 1]

Which of these ions has the greatest ionic radius?

A

N3−\mathrm{N}^{3-}

B

F−\mathrm{F}^{-}

C

Na+\mathrm{Na}^{+}

D

Al3+\mathrm{Al}^{3+}

Question 10

[Maximum number: 1]

Which of these ions has the greatest polarising power?

A

S2−\mathrm{S}^{2-}

B

Cl−\mathrm{Cl}^{-}

C

K+\mathrm{K}^{+}

D

Ca2+\mathrm{Ca}^{2+}

Question 11

[Maximum number: 1]

Which of these does not have a structure formed by a giant lattice of carbon atoms?

A

C60\mathrm{C}_{60} fullerene

B

diamond

C

graphene

D

graphite

Question 12

[Maximum number: 1]

Which of these molecules is the most polar?

A

HF

B

OF2\mathrm{OF}_{2}

C

BF3\mathrm{BF}_{3}

D

CF4\mathrm{CF}_{4}

Question 19

[Maximum number: 7]

This question is about the bonding, structure and properties of the elements in Period 3 of the Periodic Table and their compounds.

Question 19(b)

(a)

Aluminium has the greatest electrical conductivity of the Period 3 elements.

[ 3 ]

Question 19(b)(i)

(i)

Describe how metals conduct electricity.
(2)

[ 2 ]

Question 19(b)(ii)

(ii)

Give a possible reason why aluminium has a higher electrical conductivity than sodium.
(1)

[ 1 ]

Question 19(c)

(b)

Aluminium is extracted by the electrolysis of aluminium oxide in the liquid state.

[ 4 ]

Question 19(c)(i)

(i)

Draw a dot-and-cross diagram to show the bonding in aluminium oxide. Show outer shell electrons only.

[ 3 ]

Question 19(c)(ii)

(ii)

Give a reason why aluminium oxide must be in the liquid state before electrolysis can occur.

[ 1 ]

Question 19

[Maximum number: 10]

This question is about the structure and bonding of Group 5 chlorides.

Question 19(a)

(a)

Nitrogen trichloride, NCl3\mathrm{NCl}_{3}, has a molecular structure.

The displayed formula of a molecule of NCl3\mathrm{NCl}_{3} is shown.

Question image

Complete the table for this molecule.
(3)

Table
[ 3 ]

Question 19(b)

(b)

Under standard conditions, phosphorus(V) chloride ( PCl5\mathrm{PCl}_{5} ) is a solid made up of PCl4+\mathrm{PCl}_{4}^{+}cations and PCl6−\mathrm{PCl}_{6}^{-}anions.

Antimony (V) chloride (SbCl5)\left(\mathrm{SbCl}_{5}\right) is a liquid made up of SbCl5\mathrm{SbCl}_{5} molecules.

[ 4 ]

Question 19(b)(i)

(i)

Explain why PCl5\mathrm{PCl}_{5} has a higher melting temperature than SbCl5\mathrm{SbCl}_{5}.

[ 2 ]

Question 19(b)(ii)

(ii)

Draw a dot-and-cross diagram to show the bonding in a molecule of SbCl5\mathrm{SbCl}_{5}.

Use dots (•) to represent the Sb electrons, and crosses (x) to represent the Cl electrons. Show outer electrons only.

[ 2 ]

Question 19(c)

(c)

At low temperatures, SbCl5\mathrm{SbCl}_{5} converts to Sb2Cl10\mathrm{Sb}_{2} \mathrm{Cl}_{10} which contains dative covalent bonds.

[ 2 ]

Question 19(c)(i)

(i)

State what is meant by the term dative covalent bond.

[ 1 ]

Question 19(c)(ii)

(ii)

Complete the diagram to show the dative covalent bonds in Sb2Cl10\mathrm{Sb}_{2} \mathrm{Cl}_{10}.

Question image
[ 1 ]

Question 19(d)

(d)

Arsenic also forms a pentachloride with the formula AsCl5\mathrm{AsCl}_{5}.

Give one possible reason why nitrogen is the only Group 5 element that does not form a pentachloride.
(1)
(Total for Question 19 = 10 marks)

[ 1 ]

Question 19

[Maximum number: 4]

This question is about the compound ammonium dichromate(VI), (NH4)2Cr2O7\left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}.

Question 19(c)(i)

(a)

Draw a dot-and-cross diagram of the ammonium ion.

Use dots (∙)(\bullet) for the nitrogen electrons and crosses (x) for the hydrogen electrons.

[ 2 ]

Question 19(c)(ii)

(b)

Explain the shape of the ammonium ion using electron-pair repulsion theory.
(2)

[ 2 ]