Question

An aqueous solution of $X$ is added slowly to an aqueous solution of $Y$ as shown in List I. The variation in conductivity of these reactions is given in List II. Match list I with List II and select the correct answer using the code given below the lists :

	List I		List II
P.	$(\underset{X}{C_2{H}_5{)}_{3}N}+\underset{Y}{C{H}_{3}COOH}$	1.	Conductivity decreases and then increases
Q.	$\underset{X}{KI\left(0.1M\right)}+\underset{Y}{AgN{O}_3\left(0.01M\right)}$	2.	Conductivity decreases and then does notchange much
R.	$\underset{X}{C{H}_{3}COOH}+\underset{Y}{KOH}$	3.	Conductivity increases and then does notchange much
S.	$\underset{X}{NaOH}+\underset{Y}{HI}$	4.	Conductivity does not change much andthen increases

	P	Q	R	S
(A)	3	4	2	1
(B)	4	3	2	1
(C)	2	3	4	1
(D)	1	4	3	2

• A. $\left(B\right)$
• B. $\left(D\right)$
• C. $\left(C\right)$
• D. $\left(A\right)$

Answer 1

The correct option is D $\left(A\right)$

Firstly it decreases due to nutrilization of $C{H}_{3}COOH$ and replacement of $H^{+}$ by $(C_2{H}_5{)}_3\stackrel{+}{N}H$ but thereafter buffer formation takes place and $\left[H^{+}\right]$ becomes constant and increases hence conductivity increases but after equivalence point $(C_2{H}_5{)}_{3}N$ is not ionized due to much higher concentration of $(C_2{H}_5{)}_3\stackrel{+}{N}$in solution.


$AgN{O}_3+KI\to AgI\left(S\right)+KN{O}_3$

Initially only $A{g}^{+}$ is replaced by $K^{+}$ hence conductivity remain the same thereafter equivalence point $\left[K^{+}\right]$ increases hence conducitity increases.

Initially conducitity decreases due to replacement of $O{H}^{–}$ by $C{H}_{3}CO{O}^{–}$ and then almost constant due to buffer formation

Decreases due to removal of $H^{+}$ by $N{a}^{+}$ then increases due to $O{H}^{–}$.