8. An indicator is a substance which, by changing colour, can show whether another substance is an acid or a base.
9. A neutralisation reaction is one where an acid and a base react to produce a salt and water.
10. A titration is used to find out how much acid is needed to neutralise a base in a neutralisation reaction.
Questions and Exercises K C
Key Concepts Rewrite the following sentences in your copybook and fill in the blanks. 1. Acids have a ____________ taste. 2. Acids turn ____________ litmus ____________. 3. Bases that dissolve in water are called ____________. 4. The ____________ symbol is the warning symbol used for acids and bases. 5. The ____________ ____________ is used to show how acidic or basic substances are. 6. Neutral substances have pH ____________. 7. ____________ indicator can be used to find the ____________ of a substance. 8. Match each of these labels (i)–(v) with the correct letter on the pH scale diagram below. (i) Strong acid
(ii) Strong base (iii) Weak acid (iv) Weak base (v) Neutral
9. In a ____________ reaction an acid and base react to form a ____________ and water. 10. In a titration a ____________ is used to accurately measure the volume of base. 11. In a titration a ____________ is used to accurately measure the volume of acid. 12. Identify a neutralisation reaction that happens in the human body: ____________.
K U
Knowledge and Understanding 1. ‘Concentrated bases are just as harmful as acids.’ Discuss this statement.
2. Name two substances that are produced by a neutralisation reaction between an acid and a base. What method of separation can be used to separate these two substances?
