(a) Define an acid and a base. Give two examples of each.
(b) Give the names and formulae of two strong bases and two weak bases.
(c) What type of ions are formed:
(i) when an acid is dissolved in water?
(ii) when a base (or alkali) is dissolved in water?
b>(d) Write the neutralisation reaction between acids and bases in terms of the ions involved.
(e) Write any two important uses of bases
(a) Acids are substances when dissolved in water dissociates completely to produce hydrogen ions(H+). They taste sour and turns blue litmus paper to red.
Eg: Hydrochloric acid, HCl and Sulphuric acid, H2SO4
Bases are substances when dissolved in water partially dissociates to produce hydroxide ions(OH-). They taste bitter and changes red litmus paper to blue.
Eg: Sodium hydroxide, NaOH and Magnesium hydroxide, Mg(OH)2
(b) Strong bases are Sodium hydroxide, NaOH and Potassium hydroxide, KOH.
Weak bases are Calcium hydroxide, Ca(OH)2 and Ammonium hydroxide, NH4OH.
(c) (i) Hydrogen ions (H+) are formed when an acid dissolves in water.
(ii) Hydroxide ions(OH-) are formed when the base dissolves in water.
(d) Acids + Base --> Salt and Water
$H^+(aq) + OH^–(aq) → H_2O(l)$
(e) Two important uses of bases are given below:
- Bases like sodium hydroxide is used to manufacture soap, paper.
- Bases like calcium hydroxides are used to manufacture bleaching powder.
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