Chapter 3 Practice Paper: Ionic, covalent and metallic bonding — question paper

Section A: Multiple-choice questions[10 marks]

Choose one answer for each question. Each question is worth 1 mark.

1. 1

   Aluminium fluoride contains Al³⁺ and F⁻ ions. Its formula is

   1. AAlF
   2. BAlF₃
   3. CAl₃F
   4. DAlF₂
   ( )
2. 2

   In the ionic lattice of potassium oxide, the attraction holding the structure together is between

   1. Ashared electron pairs and nuclei
   2. Bdelocalised electrons and metal ions
   3. CK⁺ and O²⁻ ions
   4. Dwhole K₂O molecules
   ( )
3. 3

   Hydrogen chloride gas boils at −85 °C. When it boils,

   1. Athe intermolecular forces between molecules are overcome
   2. Bthe H–Cl bonds break
   3. Cions are set free
   4. Delectrons are transferred
   ( )
4. 4

   Which solid conducts electricity?

   1. ASolid sodium chloride
   2. BSolid iodine
   3. CSolid silicon dioxide
   4. DSolid zinc
   ( )
5. 5

   Propanone is a simple molecular liquid. Which statement about propanone is correct?

   1. AIt conducts when molten
   2. BIts covalent bonds break when it evaporates
   3. CIt has weak forces between its molecules
   4. DIt is an ionic compound dissolved in water
   ( )
6. 6

   In a dot-and-cross diagram of ammonia, NH₃, the nitrogen atom keeps

   1. Ano lone pairs
   2. Bone lone pair
   3. Ctwo lone pairs
   4. Dthree lone pairs
   ( )
7. 7

   Steel is harder than pure iron because the carbon atoms added to iron

   1. Aform covalent bonds with iron
   2. Bsupply extra delocalised electrons
   3. Creplace some iron nuclei
   4. Ddistort the regular layers so they cannot slide
   ( )
8. 8

   A substance melts at 35 °C and does not conduct in any state. Its structure is most likely

   1. Asimple molecular
   2. Bgiant ionic
   3. Cgiant covalent
   4. Dmetallic
   ( )
9. 9

   Which pair of substances are both giant covalent structures?

   1. AGraphite and sodium fluoride
   2. BDiamond and silicon dioxide
   3. CIce and dry ice
   4. DCopper and brass
   ( )
10. 10

    The main limitation of a dot-and-cross diagram for a covalent molecule is that it

    1. Ashows the wrong number of bonds
    2. Bcannot show shared pairs
    3. Cimplies electrons belong to particular atoms
    4. Donly works for metals
    ( )

Section B: Structured questions[20 marks]

Answer all questions in the spaces provided.

1. 11

   Calcium reacts with oxygen to form calcium oxide.

   1. (a)

      Calcium is in Group 2 and oxygen in Group 6. State the charge on each ion formed and how each charge arises.

      [2]
   2. (b)

      Write the formula of calcium oxide and explain how the charges balance.

      [2]
   3. (c)

      Describe the structure of solid calcium oxide and explain its very high melting point (2570 °C).

      [2]
2. 12

   A student melts four white solids in turn and tests each molten sample with a conductivity circuit. The results are shown.

   Conductivity of molten solids

   Solid	Molten sample conducts?
   Potassium bromide	Yes
   Stearic acid (a wax)	No
   Copper(II) sulfate	Yes
   Iodine	No

   1. (a)

      Explain why molten potassium bromide conducts, naming the moving particles.

      [2]
   2. (b)

      Explain why molten stearic acid does not conduct.

      [2]
   3. (c)

      Predict, with a reason, whether solid potassium bromide conducts.

      [1]
   4. (d)

      Copper(II) sulfate solution also conducts. State what this shows about the particles in solution.

      [2]
3. 13

   A jewellery catalogue lists pure silver and sterling silver (silver alloyed with copper).

   1. (a)

      Explain why pure silver conducts electricity.

      [2]
   2. (b)

      Explain why sterling silver is harder than pure silver.

      [3]
   3. (c)

      Both metals are described as malleable. State what happens to the layers of ions when a metal is hammered into shape.

      [2]