3.26 Test your knowledge

Natural sciences

Reactions that occur between different kinds of matter: acids and bases

Educator section

Memorandum

1. Bitter; slippery/smooth

2. Yellow

3. Indicator

4. Alkali

5. Lime; neutralise

6. Saltpetre; phosphorous

7. Universal indicator

Leaner section

Content

Activity: test your knowledge [lo 2.1]

You may refer to the contents of the module to help you with the following closing exercises, which will serve as a summary of the main facts to be used when you prepare for the module test.

1. Bases taste __________________________ and feel ____________________

2. When the acidity or alkalinity of a substance has to be established, it can be

added to a Bromothymol blue solution. If the colour changes to__________________

we know that the added substance is an acid.

3. A _________________________ e.g. black tea, can also be used to establish whether a substance is an acid or a base.

4. When a little caustic soda is dissolved in water and a few drops of this solution

are placed on red litmus paper the paper will become blue. This indicates that

caustic soda is_________________________________________________________

5. Most crops, and vegetables in particular, need neutral soils for optimal growth.

If the soil contains too much acid, farmers add __________________________to the

soil to _______________________________________________ the acid in the soil.

6.___________________________________________ acid is present in plastics and

________________________________________ acid is used to flavour cold drinks.

7. A ________________________ is used to determine the level of alkalinity or acidity in substance.

Assessment

Learning Outcome 2: The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard 2.1: We know this when the learner recalls meaningful information: the minimum requirement is an ability to recall definitions and complex facts.