Chemguide: Support for CIE A level Chemistry
Learning outcome 3.2(a)
This statement is in two parts and deals with simple covalent bonding, and co-ordinate (dative covalent) bonding.
Before you go on, you should find and read the statement in your copy of the syllabus.
Learning outcome 3.2(a)(i)
This covers simple covalent bonding in terms of dot and cross diagrams.
You should read a part of the page which looks at covalent bonding - single bonds.
Stop when you get to the heading which says "A more sophisticated view of covalent bonding". We will come back to that later on in this section. Up to that point, you will have come across hydrogen, chlorine, hydrogen chloride and methane from the syllabus statement.
Then follow the link at the bottom of the page to find out about double bonding in oxygen, carbon dioxide and ethene. All you need to read for now on that page is the first section. Ignore everything when it starts to get more sophisticated.
Learning outcome 3.2(a)(ii)
This covers co-ordinate covalent bonding, also called dative covalent bonding. It doesn't matter which of these terms you have been taught - you must be familiar with both of them, and realise that they mean exactly the same thing.
You should read a part of the page which looks at co-ordinate (dative covalent) bonding.
The syllabus only mentions the ammonium ion, and the bonding in the aluminium chloride dimer. That means that you must be familiar with both of those. However, you might be asked about other things as well if they involve the same principle of one atom donating both electrons to the bonding pair. So look at the other examples, and make sure they make sense to you.
Make sure that you understand everything down as far as (but not including) "The bonding in hydrated metal ions". All that you will eventually have to know from the rest of the page is the bonding in carbon monoxide. Don't worry about it for now.
© Jim Clark 2010 (last modified March 2014)