Calculate $pH$ of a buffer prepared by adding $10 \,mL$ of $0.10 \,M$ acetic acid to $20\, mL$ of $0.1\, M$ sodium acetate [$pK_a (CH_3COOH) = 4.74]$
- 3
- 4.44
- 4.74
- 5.04
The Correct Option is D
Solution and Explanation
The number of millimoles of \(CH_3COOH\) is calculated as \(0.1 \times 10 = 1.0\), while the millimoles of \(CH_3COONa\) is calculated as \(0.1 \times 20 = 2.0.\)
Using the Henderson-Hasselbalch equation:
\(pH = pK_a +log\frac{[conjugate\space base]}{[acid]} \)
\(= 4.74 + log(\frac{2}{1}) \)
\(=4.47+0.30=5.04\)
Top Questions on Buffer Solutions
- Given below are two statements:
Statement (I) : A Buffer solution is the mixture of a salt and an acid or a base mixed in any particular quantities.
Statement (II) : Blood is naturally occurring buffer solution whose pH is maintained by $H_2CO_3/HCO_3^-$ concentrations.
In the light of the above statements, choose the correct answer from the options given below.- JEE Main - 2024
- Chemistry
- Buffer Solutions
- If the $pKa$ of lactic acid is $5$ , then the $pH$ of $0.005 \,M$ calcium lactate solution at $25^{\circ} C$ is ______ $\times 10^{-1}$ (Nearest integer) Lactic acid
- JEE Main - 2023
- Chemistry
- Buffer Solutions
- A litre of buffer solution contains $01$ mole of each of $NH _3$ and $NH _4 CL$ On the addition of $002$ mole of $HCl$ by dissolving gaseous $HCl$, the $pH$ of the solution is found to be ____ $\times 10^{-3}$ (Nearest integer) [Given : $pK _5\left( NH _3\right)=4745$ $ \log 2=0301$ $\log 3=0477$ $T =298 K ]$
- JEE Main - 2023
- Chemistry
- Buffer Solutions
- The dissociation constant of bromocresol purple indicator is 3.981 × 10-7 at 0° C. The indicator when added to a buffer solution gave a colour matched with 50% basic colour and rest matched with acidic colour. The pH of buffer is:
[log 3.98 = 0.5999]- CUET (PG) - 2023
- Chemistry
- Buffer Solutions
- Class XII students were asked to prepare one litre of buffer solution of pH \(8.26\) by their Chemistry teacher. The amount of ammonium chloride to be dissolved by the student in \(0.2\) M ammonia solution to make one litre of the buffer is (Given : \(pK_b\) \((NH_3)\) = \(4.74\), Molar mass of \(NH_3\) = \(17\) g \(mol^{–1}\), Molar mass of \(NH_4Cl\) = \(53.5\) \(g\) \(mol^{–1}\))
- JEE Main - 2022
- Chemistry
- Buffer Solutions
Questions Asked in VITEEE exam
- Two identical blocks A and B, each of mass 'm' resting on a smooth floor are connected by a light spring of natural length L and spring constant K, with the spring at its natural length. A third identical block 'C' (mass m) moving with a speed v along the line joining A and B collides with A. the maximum compression in the spring is
- VITEEE - 2023
- work, energy and power
- Assertion :
The binding energy of the nucleus increases with the increase in atomic number.
Reason :
Heavier elements have a greater number of non-radioactive isotopes than radioactive isotopes. - The half-life of radioactive radon is 3.8 days. The time at the end of which \(\frac{1}{20}th\) of the Radon sample will remain undecayed is (given log10e=0.4343)
- Which element has more electron gain enthalpy among chalcogen group?
- VITEEE - 2022
- sulphur
- Coin is tossed till heads is obtained what is expectation of no. of coin tosses
- VITEEE - 2022
- Random Variables
Concepts Used:
Buffer solutions
The buffer solution is a solution that is able to maintain its Hydrogen ion concentration (pH) with only minor changes on the dilution or addition of a small amount of either acid or base. They are used in fermentation, food preservatives, drug delivery, printing, the activity of enzymes and many more.
Buffer solutions are aqueous solutions containing a weak acid and its salt - acid buffer or a weak base and its salt - base buffer.
Types of Buffer Solution
Acidic Buffers
These solutions are used to maintain acidic environments. Also, it has acidic pH and is prepared by mixing a weak acid and its salt with a strong base. An aqueous solution of an equal concentration of acetic acid and sodium acetate has a pH of 4.74.
Alkaline Buffers
These solutions are used to maintain basic conditions. It has a basic pH and is prepared by mixing a weak base and its salt with strong acid. The aqueous solution of an equal concentration of ammonium hydroxide and ammonium chloride has a pH of 9.25.
SUBSCRIBE TO OUR NEWS LETTER
