Buffer Solutions

Which of the following statement(s) is/are correct?

(A) The $\mathrm{pH}$ of $1\times {10}^{–8 }\mathrm{M} \mathrm{HCl}$ solution is $8$.

(B) The conjugate base of ${\mathrm{H}}_2{\mathrm{PO}}^{4-}$ is ${\mathrm{HPO}}_4^{2-}$.

(C) ${\mathrm{K}}_{\mathrm{w}}$ increases with increase in temperature.

(D) When a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, $\mathrm{pH}=\frac{1}{2}{\mathrm{pK}}_{\mathrm{a}}$.

Choose the correct answer from the options given below:

Equal volumes of $0.5 \mathrm{N}$ acetic acid and $0.5 \mathrm{N}$ sodium acetate are mixed. What is the $\mathrm{pH}$ of resultant solution?

(${\mathrm{pK}}_{\mathrm{a}}$ of acetic acid $=4.75$)

${\mathrm{H}}_3{\mathrm{PO}}_4\left({\mathrm{Ka}}_1={10}^{-3}, {\mathrm{Ka}}_2={10}^{-8}, {\mathrm{Ka}}_3={10}^{-12}\right)$ can form $3$ types of buffer in $3$ different ranges of $\mathrm{pH}$ $\left({\mathrm{H}}_3{\mathrm{PO}}_4, {\mathrm{H}}_2{\mathrm{PO}}_4^{-}\right),\left( {\mathrm{H}}_2{\mathrm{PO}}_4^{-}, {\mathrm{HPO}}_4^{2-}\right), \left( {\mathrm{HPO}}_4^{2-}, {\mathrm{PO}}_4^{3-}\right)$

Most appropriate buffer was chosen to introduce buffer action at $\mathrm{pH}=7.4$. Find volume of $0.1 \mathrm{M} \mathrm{NaOH}$ to be added to $50 \mathrm{mL} 0.1 \mathrm{M} {\mathrm{H}}_3{\mathrm{PO}}_4$ to have a buffer of $\mathrm{pH}=7.4$.

The $\mathrm{pH}$ of the buffer solution at maximum buffer capacity

The pH of the solution can be kept constant with the help of

Which among the following pairs constitute a buffer?

Addition of sodium hydroxide solution to a weak acid (HA) results in a buffer of pH 6. If ionization constant of HA is ${10}^{-5}$, the ratio of salt to acid concentration in the buffer solution will be:

A buffer solution can be prepared by mixing equal volumes of

Among the following, the correct statement is

What is the concentration of sodium acetate that needs to be added to a $0.01 \mathrm{M}$ solution of acetic acid with equal volumes to give a solution of $\mathrm{pH}=5.5?$

$\left({\mathrm{pK}}_{\mathrm{a}}\text{ of }{\mathrm{CH}}_3\mathrm{COOH}=4.5\right)$

Choose the wrong statement from the following:

For preparing a buffer solution of $\mathrm{pH}=9$, by mixing ammonium chloride and ammonium hydroxide, the ratio of concentrations of salt and base should be_______ $\left({\mathrm{K}}_{\mathrm{b}}={10}^{-3}\right)$

Which may be added to one litre of water to act as a buffer :

$2.5 \mathrm{mL}$ of $\frac{2}{5}\mathrm{M}$ weak mono acidic base (${\mathrm{K}}_{\mathrm{b}}=1\times {10}^{-12}$ at $25°\mathrm{C}$) is titrated with $\frac{2}{15}\mathrm{M}$ $\mathrm{HCl}$ in water at $25°\mathrm{C}$. The concentration of ${\mathrm{H}}^{+}$ at equivalent point is : (${\mathrm{K}}_{\mathrm{w}}=1\times {10}^{-14}$ at $25°\mathrm{C}$)

${\mathrm{K}}_{\mathrm{a}}$ of undefined is undefined and undefined of undefined is undefined. The $\mathrm{pH}$ of amonium acetate is ?

${\mathrm{CH}}_3{\mathrm{NH}}_2\left(1.2 \mathrm{mole},{\mathrm{pK}}_{\mathrm{b}}=3.3\right)$ is added to $0.08 \mathrm{moles}$ of $\mathrm{HCl}$ and the solution is diluted to one litre, resulting $\mathrm{pH}$ of solution is :-

Which of the following forms a buffer solution?

Which of the following pairs constitute a buffer?

To prepare a buffer of $\mathrm{pH} 8.26$,  amount of ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4$ that needs to be added to $500 \mathrm{ml}$ of  $0.01{\mathrm{MNH}}_4\mathrm{OH}$ solution $\left[\left(\mathrm{pKa}\right){\mathrm{NH}}_4^{+}=9.26\right]$ is :-

A student prepares 2 L buffer solution of 0.3 M NaH₂PO₄ and 0.3 M Na₂HPO₄. The solution is divided in half between the two compartments (each containing 1 L buffer) of an electrolysis cell, using Pt electrodes. Assume that the only reaction is the electrolysis of water and the electrolysis is carried out for 200 min with a constant current of 0.965 A.

$\left[\text{Assume that}{\text{ pK}}_{\text{a}\left({\text{H}}_2{\text{PO}}_4^{\ominus }\right)}=\text{7.2}\right]$  [Given log 2.33 = 0.37]

pH at anode is