Spot the bonding

A variety of types of diagram are used in this activity, as it is important for students to be able to interpret and use various ways of representing chemical species 

Activity

This exercise comprises of a set of diagrams showing a range of chemical species and systems. For each diagram: either write the name or names of the type or types of bonding present, or write none (if there is no chemical bonding) or do not know if you are unsure. 

Answers

The following answers are suitable for students who have studied bonding at post-16 level. Where the Spot the bonding probe is used with students at an earlier stage, then they should not be expected to provide the full range of responses. 

1. Sodium chloride lattice: ionic 
2. Diamond lattice: covalent 
3. Benzene molecule: covalent, delocalised 
4. Copper lattice: metallic 
5. Hydrogen fluoride molecule: covalent, polar 
6. Liquid water: covalent, polar; hydrogen, covalent, van der Waals forces, dipole-dipole forces 
7. Fluorine molecule: covalent 
8. Silver nitrate solution: covalent, polar; hydrogen, dipole-dipole, van der Waals forces, solvent-solute interactions 
9. Oxygen gas: covalent (double/sigma + pi), van der Waals forces 
10. Sulfur molecule: covalent
11. Sodium atom: no chemical bonding (although intra-atomic forces of similar nature)
12. Aluminium chloride dimer: polar, including dative (coordinate) covalent
13. Carbon dioxide molecule: covalent, polar (double/sigma + pi) 
14. Ethanoic acid dimer: covalent, polar, hydrogen
15. Iodine lattice: covalent, van der Waals forces
16. Ammonia molecule: covalent, polar
17. Magnesium oxide lattice: ionic 
18. Liquid hydrogen chloride: covalent, polar, van der Waals forces

• Where a bond has significant polarity, it could be described as polar rather than covalent (or polar covalent.)
• The term van der Waals forces has been used for induced dipole-dipole forces.
• Students may forget to mention van der Waals forces in cases where they recognise hydrogen-bonds are present (ie items 6, 8 and 18). 
• The presence of some covalent character in the magnesium oxide lattice may be spotted by some students. 

Notes

For the full version of this chapter, see downloads below.