Buffer Solutions

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_______ $\left({\mathrm{K}}_{\mathrm{b}}={10}^{-3}\right)$

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

For next two question please follow the same

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 cathode is

$100 \mathrm{mL}$ of $0.10 \mathrm{M}$ ${\mathrm{NH}}_4\mathrm{OH}$ mixed with $100 \mathrm{mL}$ of $0.05 \mathrm{M}$ $\mathrm{HCl}$ solution

The $\mathrm{pH}$ of $100 \mathrm{mL}$ of $0.10 \mathrm{M}$ $\mathrm{NaOH}$ mixed with $100 \mathrm{mL}$ $0.10 \mathrm{M}$ ${\mathrm{CH}}_3\mathrm{COOH}$ solution is

Identify the buffer solution among the following.

Calculate the $\mathrm{pH}$ of a buffer solution prepared by adding $10 \mathrm{mL}$ of  $0.1 \mathrm{M} {\mathrm{CH}}_3\mathrm{COOH}$ and $20 \mathrm{mL}$ of $0.1 \mathrm{M}$ sodium acetate.
(Given: ${\mathrm{pK}}_{\mathrm{a}}$  of ${\mathrm{CH}}_3\mathrm{COOH}=4.74$)

What will be the $\mathrm{pH}$ of resultant mixture when $20\mathrm{ml}$ of $0.1\mathrm{M}{\mathrm{H}}_2{\mathrm{SO}}_4$ solution is added to $30\mathrm{mL}$ of $0.2\mathrm{M}{\mathrm{NH}}_4\mathrm{OH}$ solution ?

Given:- $\left[{\mathrm{pk}}_{\mathrm{b}}\mathrm{ }\mathrm{of}\mathrm{ }{\mathrm{NH}}_4\mathrm{OH}=4.7\right]$

Calculate $\mathrm{pH}$ of solution containing $0.3 \mathrm{M}$  ${\mathrm{NH}}_4^{+}$ , $0.2 \mathrm{M}$ ${\mathrm{NH}}_4\mathrm{OH}$ $\left({\mathrm{p}}_{{\mathrm{K}}_{\mathrm{b}}}=4.74\right)$ and  $0.01 \mathrm{M} \mathrm{HCl}$ having volume $100 \mathrm{ml}$ is

A basic buffer is prepared with maximum buffer capacity. Calculate the ratio of base to salt to be taken to increase its $\mathrm{pOH}$ by two.

A buffer solution contains equal concentration of ${\mathrm{X}}^{-}$ and $\mathrm{HX}, {\mathrm{K}}_{\mathrm{b}}$ for ${\mathrm{X}}^{-}$ is ${10}^{-10}.$ Calculate the $\mathrm{pH}$ of the buffer.

 Find the volume of HA in 300ml of buffer if the pH of a mixture of 1M HA(pK_b=4.2) and 1M NaA is 4.5.

What will be ratio of salt to acid concentration in the buffer solution of $\mathrm{pH}=6$  formed due to addition of sodium hydroxide solution to a weak acid $\left(\mathrm{HA}\right)$.  

Given Ionisation constant of $\mathrm{HA}$  is ${10}^{-5}.$

$500 \mathrm{mL}$ of $0.2 \mathrm{M}$ aqueous solution of acetic acid is mixed with $500 \mathrm{mL}$ of $0.2 \mathrm{M} \mathrm{HCl}$ at ${25}^{\mathrm{o}}\mathrm{C}$ and $6 \mathrm{g} \mathrm{NaOH}$ is added to this mixture. Assuming there is no change in the volume on mixing, determine the $\mathrm{pH}$ of the resultant mixture. (Given: Atomic weight: $\mathrm{Na} =23 \mathrm{u}, \mathrm{O} =16 \mathrm{u}, \mathrm{H} = 1 \mathrm{u};$ for acetic acid ${\mathrm{K}}_{\mathrm{a}}= 1.75 \mathrm{x} {10}^{-5}$)

The number of buffers formed during the neutralization process of ${\mathrm{H}}_3{\mathrm{PO}}_4 \mathrm{and} \mathrm{NaOH}$, will be-

The ionisation constant of $\mathrm{NH}_{4}^{+}$ in water is $5.6 \times 10^{-10} \mathrm{at}$ $25^{\circ} \mathrm{C} .$ The rate constant for the reaction of $\mathrm{NH}_{4}^{+}$ and $\mathrm{OH}^{-}$ to form $\mathrm{NH}_{3}$ and $\mathrm{H}_{2} \mathrm{O}$ at $25^{\circ} \mathrm{C}$ is $3.4 \times 10^{10}$ litre

$\mathrm{mol}^{-1} \mathrm{sec}^{-1} .$ If equilibrium constant of water at $25^{\circ} \mathrm{C}$ is $1.8 \times 10^{-16},$ thenThe $\mathrm{pH}$ of a mixture of

$0.1 \mathrm{M} {\mathrm{NH}}_4\mathrm{OH}$ and
$0.1\mathrm{M} {\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4$ solution is $\left[{\mathrm{K}}_{\mathrm{a}} \text{of }{\mathrm{NH}}_4^{+}\text{ is} 5.6\times {10}^{-10} \text{and} \log 1.78=0.25\right]$