Question

Choose the correct set of True/False for the following statement:
i. Silver Chloride is more soluble in a very concentrated sodium chloride solution than in pure water.
ii. The pH of a buffer solution does not change on the addition of a small amount of an acid or a base.
iii. Addition of \[N{H_4}Cl\] does not affect the pH of a solution of $N{H_4}OH$.
iv. Degree of Hydrolysis of ammonium acetate does not depend upon the concentration of ammonium acetate solution.
v. A mixture of acetic acid and sodium acetate can act as a buffer solution.
A. TTFTT
B. FTTTF
C. TFTF
D. FTTTT

Answer 1

Hint: According to common ion effect, if an ionic salt is in equilibrium in a solution then if the salt-containing similar ions are added to it, then its equilibrium shifts backward, and precipitation occurs. The common ion effect follows Le Chatelier's principle.

Complete step by step answer:
Complete step by step solution: For the case of point (i) that says Silver Chloride ($AgCl$) is more soluble in Concentrated sodium chloride ($NaCl$) than in pure water, we will proceed by discussing the dissociation. Silver Chloride on dissociation gives the ions of Silver and Chlorine as shown below:
\[AgCl \rightleftharpoons A{g^ + } + C{l^ - }\]
Also, in the case of concentrated Sodium chloride, ions of sodium and chlorine are received as shown below:
$NaCl \rightleftharpoons N{a^ + } + C{l^ - }$
So, if we tend to dissolve $AgCl$ in conc. $NaCl$, $C{l^ - }$ ions will be common, and thus by common ion effect, the reaction will start moving backward. Hence we can say $AgCl$ is not soluble in conc. $NaCl$due to the common ion effect instead, it is soluble in pure water. Hence the statement (i) is wrong.
For the case of the statement (ii) that says the pH of a buffer solution does not change on the addition of a small amount of an acid or a base, it is true as buffer solutions are the solution that resists the change in their pH. Hence statement (ii) is correct.
Now for the case of the statement (iii) that says Addition of \[N{H_4}Cl\] does not affect the pH of a solution of $N{H_4}OH$, \[N{H_4}Cl\] is a solution of a weak base and strong acid and $N{H_4}OH$ is a weak base. Hence together they both form a buffer solution and it will resist the change in its pH. Hence this statement is also correct.
For the case of statement (iv) that says Degree of Hydrolysis of ammonium acetate does not depend upon the concentration of ammonium acetate solution, as we know degree of hydrolysis does not depend on concentration, so the statement is correct.
For the case of statement (v) that says, a mixture of acetic acid and sodium acetate can act as a buffer solution as we know that acetic acid ($C{H_3}COOH$) is weak acid and sodium acetate ($C{H_3}COONa$) is a salt of weak acid and strong base and such combination tends to form a buffer solution, so this statement is also correct.
Hence the correct order of true and false for the statements is FTTTT

Hence the correct option is D.

Note: Buffer Solution is a solution that contains a mixture of weak acid or base and its salt in water. They tend to resist the change in pH due to addition of a small amount of acid or base or in case of dilution. One common example of Buffer solution is Human blood.