Properties of acids, bases and neutrals

• Tell the learners that they will learn about acids and bases which have specific properties that assist us to distinguish them from one another.
• Show the following 4 short video clips / select what you would like to show:

Video Clip 3:  Knowing Acids [0:50min.].

Video Clip 4:  Acids Found In Nature. [0.50 min.].

Video Clip 5:  Bases. [0:38 min.].

Video Clip 6:  Bases in Our Everyday Life. [1:05 min.].

• Inform the learners about the importance of knowing the properties of the different chemicals in order to be aware whether they are dangerous or safe and their usage.
• Share the following interesting fact:
  • The word ‘acid’ is derived from two Latin words, namely acidus and acere.
• Remind the learners to be attentive when they watch the presentation, because they will do a practical identification [items/ pictures on an A4 page] and complete an activity afterwards.
• Present an overview of the different properties of acids, bases and neutrals by using Presentation 2: Properties of acids, bases and neutrals.

• The learners are grouped and receive 3-4 items / an A4 page with pictures which they must classify randomly as acids, bases and neutrals.
• Possible items: Aspirin; Vanish; oven cleaner; face soap; bicarbonate of soda; salt; fruit; oil; buttermilk; water; chillies; mouth wash; vinegar; etc.
• Learners place the items in columns [bases; acids; neutrals] or cut it out and then paste it into columns.
• Complete Worksheet B: Properties of acids and bases.
• Teacher to use Worksheet B: Memorandum to mark the learners’ work.

• The following video clips are also interesting and informative. It can be shown to the learners if there is sufficient time:

Video Clip 7:  Preparation of a Beetroot Indicator [1:18 min.].      

Video Clip 8:  Turmeric as indicator | Acids & Bases | Chemistry [2.28 min.].

Video Clip 9:  Neutralization in Our Daily Life [1.01 min.].