(i) What is buffer solution? Give an example for an acidic buffer and a basic buffer. (ii) The value of K_(sp) of two sparingy soluble salts Ni(OH)_(2) and AgCN are 2.0 times 10^(-15) " and "6 times 10^(-17) respectively. Which salt is more soluble? Explain.

(i) What is buffer solution? Give an example for an acidic buffer and

1.	(i) What is buffer solution? Give an example for an acidic buffer and a basic buffer. (ii) The value of K_(sp) of two sparingy soluble salts Ni(OH)_(2) and AgCN are 2.0 times 10^(-15) " and "6 times 10^(-17) respectively. Which salt is more soluble? Explain.
Answer» Solution :(i) 1. Buffer is a solution which consists of a mixture of weak ACID and its conjugate base (or) or a weak base and its conjugate acid. 2. This buffer solution RESISTS drastic changes in its pH upon addition of a small quantities of acids (or) bases and this ability is called buffer action. 3. Acidic buffer solution : Solution CONTAINING acetic acid and sodium acetate. BASIC buffer solution : Solution containing `NH_(4)O" and " NH_(4)Cl`. (ii) `AgCN iff Ag^(+)+CN^(-)` `K_(sp)=[Ag^(+)][CN^(-)]=6 times 10^(-17)` `Ni(OH)_(2) iff Ni^(2+)+2OH^(-)` `K_(sp)=[Ni^(2+)][OH^(-)]^(2)=2 times 10^(-15)` Let `[Ag^(+)]=S_(1), " then "[CN^(-)]=S_(1)` Let `[Ni^(2+)]=S_(2), " then "[OH^(-)]=2S_(2)` `S^(2)""_(1)=6 times 10^(-17), S_(1)=7.8 times 10^(-9)` `(S_(2))(2S_(2))^(2)=10^(-15), S_(2)=0.58 times 10^(-4)` `Ni(OH)_(2)` is more soluble than AgCN.