Question

(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?
(d) Write the neutralisation reaction between acids and bases in terms of the ions involved.
(e) Write any two important uses of bases.

Answer 1

Acids and bases are the chemicals that have a very vital role in our day-to-day life. They are both artificial like laboratory prepared and natural in various fruits and animals. There are three stories about the origin of acid and base.

Complete step by step answer:
(a ) Acids are those chemical substances that when dissolved in water they release ${H^ + }$ ions. Acids are sour in taste. Acid conducts electricity. They turn blue litmus red. Examples of acids are Acetic acid and citric acid.
Base are those chemical substances that when dissolved in water they release $O{H^ - }$ ions. They can also conduct electricity and they turn red litmus blue. Bases are bitter in taste. Examples of bases are Caustic soda and washing soda.
(b) Examples of Strong bases are Sodium hydroxide ($NaOH$), potassium hydroxide ($KOH$).
Examples of Weak bases are Calcium hydroxide ($Ca{(OH)_2}$​)), ammonium hydroxide ($N{H_4}OH$)
(c) (i) When Acid gets dissolved in water they tend to dissociate into Hydrogen ions i.e ${H^ + }$ ions.
(ii) When a base gets dissolved in water they tend to dissociate into Hydroxide ions i.e $O{H^ - }$ions.
(d) The Neutralisation reaction between acids and bases produces salt and water. This is given as;
${H^ + }\,(from\,\,acid)\, + \,\,O{H^ - }(from\,\,base)\, \to {H_2}O\,(water)$
(e) Two important use of bases are:
Sodium hydroxide ($NaOH$) is used in the manufacturing of soap, paper, and rayon while Calcium hydroxide is used in the manufacturing of bleaching powder from $CaO$ (calcium oxide).

Note:
pH scale is a parameter that is used to measure whether the given chemical is an acid or a base. If the value on the pH scale is less than $7$ then it is an acid and if the value is more than $7$ it is a base.