Syllabus Edition

First teaching 2014

Last exams 2024

|

Ionic & Covalent Bonding (DP IB Chemistry: SL)

Exam Questions

2 hours45 questions
1a1 mark

Describe the nature of ionic bonding.

1b1 mark

State the type of bonding in potassium chloride which melts at 1043 K.

1c2 marks

Describe the structure and bonding in solid magnesium oxide.

1d1 mark

Outline why solid magnesium chloride does not conduct electricity.

Did this page help you?

2a2 marks

Predict whether phosphorus(V) oxide and sodium oxide conduct electricity in their solid and molten states. Complete the boxes with “yes” or “no”.

  Phosphorus(V) oxide Sodium oxide
Solid state    
Molten state    
2b2 marks

State the formula of the compounds formed between the elements below.

i)    Sodium and sulfur:

ii)    Magnesium and phosphorus:

2c2 marks

Describe the covalent bond present in a chlorine molecule and how it is formed.

2d1 mark

Draw the Lewis (electron dot) structure of chloromethane.

Did this page help you?

3a
Sme Calculator
1 mark

Using section 8 of the data booklet to state which of the following single covalent bonds is the most polar.

C-O C-H O-H

3b1 mark

Using section 10 of the data booklet, list the following molecules in order of increasing bond length between the carbon atoms.

C2H6 C2H4 C2H2
3c1 mark

Using section 11 of the data booklet, list the following molecules in order of decreasing bond strength between the carbon atoms.

C2H6 C2H4 C2H2
3d1 mark

CO contains three covalent bonds, one of which is a coordinate bond.

Describe how a coordinate bond arises in CO.

Did this page help you?

4a2 marks

Calcium nitrate contains both covalent and ionic bonds.

State the formula of both ions present and the nature of the force between these ions.

4b1 mark

State the formula of the compound that boron forms with chlorine.

4c1 mark

Draw the Lewis structure for boron chloride.

4d1 mark

Explain why boron trichloride is able to form coordinate (covalent) bonds with other molecules. 

Did this page help you?

1a2 marks

Calcium sulfide is an ionic solid that is phosphorescent and glows in the dark after a light source is removed. 

   i) Describe the nature of the bonding in calcium sulfide. 

   ii) State one physical property of calcium sulfide.

1b3 marks

Suggest why the melting point of calcium sulfide is much higher than that of elemental calcium or sulfur.

1c4 marks

Calcium sulfide has a lattice structure similar to sodium chloride.

Describe the lattice structure of calcium sulfide and draw a representative 3D diagram.

Label each ion and use different size spheres to distinguish between the different types of ions present.

1d2 marks

State the formula of calcium phosphate and calcium hydroxide.

Did this page help you?

2a2 marks

Ammonia, NH3, is a chemical that is key in the manufacture of certain fertilisers and cleaning products.

An ammonia molecule will react with an H+ ion, to form the ammonium ion, NH4+.

Draw a Lewis (electron dot) diagram to show the bonding in the ammonium ion and name the type of bond formed between the ammonia molecule and the hydrogen ion. 

2b3 marks

Lewis (electron dot diagrams) are used to show the electron arrangement in the valence shells of covalently bonded molecules.

            Draw Lewis diagrams for the following molecules:

(i)         Hydrogen cyanide.

(ii)        Carbon dioxide.

(iii)        Boron trifluoride.

2c2 marks

Using your answer to part (b), identify and explain the species that is likely to form a coordinate covalent bond.

2d3 marks

Using your answer to part (c), Explain, with the help of a diagram, the covalent bond formed between the species in part (c) and ammonia.

Did this page help you?

3a6 marks

For each of the molecules below, draw the Lewis (electron dot) structure and use the valence shell electron pair repulsion theory (VSEPR) to predict the shape of each molecule.

Oxygen difluoride (OF2), phosphorus trifluoride, (PF3) and boron trichloride, (BCl3).

3b2 marks

Crystalline ionic compounds do not conduct electricity. 

State and explain in which states ionic compounds conduct electricity.

3c3 marks

The melting point of sodium chloride, NaCl, is 801° C. 

Explain, with reference to structure and bonding, why sodium chloride melts at such a high temperature.

3d2 marks

We can use electronegativity values to deduce whether a compound is likely to be ionic or covalent.

Use Table 7 of the Data Booklet to state and explain whether each of the following compounds are ionic or covalent:

   ICl

   SrCl2

   RbI

   HI

Did this page help you?

4a2 marks

Diimide, N2H2, is a useful reagent in organic synthesis and can be made by the thermal decomposition of azodicarboxylic acid 

         (NCOOH)2 (g) → N2H2 (g) + 2CO2 (g) 

Another useful compound of nitrogen is hydrazine, N2H4. 

Draw Lewis (electron dot) structures for diimide and hydrazine.

4b2 marks

Deduce the molecular geometry of diimide and estimate its H-N-N bond angle.

4c3 marks

List, with an explanation, the three compounds in order of increasing carbon to oxygen bond length (shortest first). 

               H3COCH3              CO              CO2       

4d2 marks

Use Table 8 of the Data Booklet to predict which bond in each of the following pairs is more polar:

   (i)         C–H or C–Cl

   (ii)        Si–Li or Si–Cl

Did this page help you?

5a3 marks

Three types of covalent bonds are present in the molecules in the following equation. 

            2C2H2 (g) + 5O2 (g) → 4CO2 (g) + 2H2O (l) 

Identify one bond in these molecules that is correctly described by the following: 

 (i)       A polar single bond. 

(ii)       A non-polar double bond. 

(iii)      A non-polar triple bond.

5b2 marks

Explain which of the bonds in part (a) is the shortest.

5c3 marks

Table 1 shows the carbon-carbon bond enthalpy values for three different hydrocarbons. 

Table 1 

Hydrocarbon

C2H6

C2H4

C2H2

Bond enthalpy /

kJ mol-1

346

614

839

Explain the difference in carbon-carbon bond enthalpy values for the three hydrocarbons.

5d2 marks

We can use electronegativity values to deduce whether a compound is likely to be pure covalent(non-polar) or polar covalent. 

Use Table 8 of the Data Booklet to state and explain whether each of the following covalent compounds are polar or non-polar:

      H2

      HCl

      CO

Did this page help you?

1a5 marks

Magnesium fluoride is a white crystalline salt that has a giant ionic lattice structure.

State whether the following substances conduct electricity when solid or molten, and explain your answers in terms of the particles involved:

  • magnesium
  • magnesium fluoride
  • boron tribromide
1b2 marks

Sodium chloride and iodine are both solids. Sodium chloride does not melt until it reaches a temperature of 1074 K yet iodine sublimes when heated gently, giving off purple vapours. Sodium chloride will conduct electricity when molten and iodine is a very poor conductor of electricity.

State the type of crystal structure for each of iodine and sodium chloride.

1c2 marks

Explain why iodine vaporises easily.

1d3 marks

Explain the differences in the electrical conductivity of sodium chloride and iodine.

Did this page help you?

2a2 marks

The nitrate (V) ion, NO3-, is a polyatomic ion, bonded by covalent bonds. 

The three oxygen atoms are bonded by one single covalent bond, one double covalent bond and one dative covalent bond.

Draw the Lewis structure for NO3-

2b2 marks

An ionic compound has the empirical formula H4N2O3

Suggest the formulae of the ions present in this compound.

2c4 marks

The compounds SO2 and MgO are both oxides but with different melting points as shown below.

Compound

Melting point / ℃

SO2

-72

MgO

2852

Describe the bonding in, and the structure of, SO2 and MgO and explain the difference in their melting points.

2d2 marks

Ammonia, NH3, has the same crystalline structure as SO2 and yet its melting point is 2℃. Explain the difference in melting point between SO2 and NH3.

Did this page help you?

3a3 marks

Silver chloride, AgCl, is a chloride compound that has uses in photography films as well as having antiseptic properties. 

Silver chloride has a high melting point and a structure similar to sodium fluoride.

Explain why, with reference to structure and bonding, why silver chloride has such a high melting point.

3b1 mark

Cyanide is a fast-acting chemical, which can be found in various forms and can have toxic effects on the body.

Draw the Lewis structure for a CN- ion. 

Show the outer electrons only.

3c3 marks

Ammonia, NH3, and boron trifluoride, BF3, react together to form NH3BF3. Each of the molecules NH3 and BF3 have different features of its electronic structure which allows them to bond together. Explain how the two molecules bond together and what type of bond is formed between NH3 and BF3.

You may use a labelled diagram to help you.

3d4 marks

Aluminium chloride, Al2Cl6, does not conduct electricity when molten but aluminium oxide, Al2O3, does. Explain this in terms of the structure and bonding of the two compounds.

Did this page help you?

4a1 mark

State why magnesium and oxygen form an ionic compound while carbon and oxygen form a covalent compound.

4b2 marks

Explain why the melting point of phosphorus(V) oxide is lower than that of sodium oxide in terms of their bonding and structure.

4c2 marks

N, N–dinitronitramide N(NO2)3, also known as trinitramide, has been identified as a potentially more environmentally friendly rocket fuel oxidant.

Using section 10 of the data booklet, outline how the length of the bond between nitrogen atoms in trinitramide compares with the bond between nitrogen atoms in nitrogen gas, N2.

4d2 marks

Describe the bonding within the carbon monoxide molecule.

Did this page help you?