Buffer Solutions

IMPORTANT

Buffer Solutions: Overview

This topic covers concepts, such as, Buffer Solutions, Need of Constant pH Solutions, Derivation of an Expression for a Basic Buffer & Buffer Capacity etc.

Important Questions on Buffer Solutions

EASY
IMPORTANT

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

EASY
IMPORTANT

Why constant pH solutions are needed?

EASY
IMPORTANT

Which of the following pairs will not constitute a buffer solution?

HARD
IMPORTANT

A buffer solution can be prepared by mixing equal volumes of

EASY
IMPORTANT

Among the following, the correct statement is

EASY
IMPORTANT

Choose the wrong statement from the following:

HARD
IMPORTANT

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.

Assume that  pK a H 2 PO 4 = 7.2   [Given log 2.33 = 0.37]

pH at anode is

HARD
IMPORTANT

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.

Assume that  pK a H 2 PO 4 = 7.2   [Given log 2.33 = 0.37]

pH at cathode is

HARD
IMPORTANT

100 mL of 0.10 M NH4OH mixed with 100 mL of 0.05 M HCl solution

HARD
IMPORTANT

The pH of 100 mL of 0.10 M NaOH mixed with 100 mL 0.10 M CH3COOH solution is

EASY
IMPORTANT

The number of moles of an acid or base added to one litre of the buffer solution so as to change its pH by one unit is called_____of the buffer.

MEDIUM
IMPORTANT

Blood is a buffer of H2CO3 and HCO3- with pH of 7.4. What will be the ratio of HCO3- to H2CO3 in blood.

HARD
IMPORTANT

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 pH of a mixture of

0.1 M NH4OH and
0.1M NH42SO4 solution is Ka of NH4+ is 5.6×10-10 and log1.78=0.25 

HARD
IMPORTANT

A buffer of acetic acid (pKa=4.8) with sodium acetate, when CH3COOH and CH3COONa are present in equivalent amounts, has a pH range of

EASY
IMPORTANT

The buffer capacity is equal to:

MEDIUM
IMPORTANT

Consider the titration of weak monobasic acid HA using 0.1 M NaOH. If initially 100 mL of 0.1 M HA is taken then find the volume of NaOH (in mL) added so that pH of mixture become equal to 5.

Question Image

 

HARD
IMPORTANT

The number of grams/weight of NH4Cl required to be added to 3 litres of 0.01 M NH3 to prepare the buffer of pH=9.45 at temperature 298 K is (Kb for NH3 is 1.85×10-5)

MEDIUM
IMPORTANT

In the neutralization process of H3PO4 and NaOH, the number of buffers formed will be-

EASY
IMPORTANT

Which one of the following mixture does not act as a buffer solution-

EASY
IMPORTANT

100 mL of a solution contains 2g of acetic acid and 3g of sodium acetate providing Ka=1.8×10-5 , then choose the correct option.