The molar conductivity of $0.007 \,M$ acetic acid is $20\, S\, cm ^{2} mol ^{-1}$. What is the dissociation constant of acetic acid? Choose the correct option.
$\left[\Lambda_{ H ^{+}}^{\circ}=350 \,S \,cm ^{2} mol ^{-1},
\Lambda_{ CH _{3} COO ^{-}}^{\circ}=50\, S\, cm ^{2} mol ^{-1}\right]$
- $1.75 \times 10^{-4}\, mol\, L ^{-1}$
- $2.50 \times 10^{-4}\, mol\, L ^{-1}$
- $1.75 \times 10^{-5}\, mol\, L ^{-1}$
- $2.50 \times 10^{-5} \, mol\, L ^{-1}$
The Correct Option is C
Solution and Explanation
$=\frac{\Lambda_{ C }}{\Lambda_{0}}=\frac{20}{350+50}=\frac{1}{20}$
$ K _{ a }=\frac{ C \alpha^{2}}{1-\alpha} $
$1-\alpha \approx 1 $
$K _{ a }= C \alpha^{2} $
$ K _{ a }=0.007 \times \frac{1}{20} \times \frac{1}{20} $
$ K _{ a }=1.75 \times 10^{-5}$
Top Questions on Conductance
- Find pH of the solution if \([H^+] = 2 \times 10^{-4} \, \text{mol/L}\)
- KEAM - 2025
- Chemistry
- Conductance
- A subatomic particle of mass \(2.2 \times 10^{-28}\) kg. Velocity = \(3 \times 10^5 \, \text{ms}^{-1}\). De Broglie wavelength?
- KEAM - 2025
- Chemistry
- Conductance
Given below are two statements:
Statement I: Mohr's salt is composed of only three types of ions—ferrous, ammonium, and sulphate.
Statement II: If the molar conductance at infinite dilution of ferrous, ammonium, and sulphate ions are $ x_1 $, $ x_2 $, and $ x_3 $ $ \text{S cm}^2 \, \text{mol}^{-1} $, respectively, then the molar conductance for Mohr's salt solution at infinite dilution would be given by $ x_1 + x_2 + 2x_3 $.- JEE Main - 2025
- Chemistry
- Conductance
- The electronic conductance depends on:
- KCET - 2025
- Chemistry
- Conductance
- Which of the following substances is a bad conductor of electricity?
Questions Asked in NEET exam
- A photon and an electron (mass \(m\)) have the same energy \(E\). The ratio \( \frac{\lambda_{\text{photon}}}{\lambda_{\text{electron}}} \) of their de Broglie wavelengths is: (\(c\) is the speed of light)
- NEET (UG) - 2025
- Dual nature of radiation and matter
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
- NEET (UG) - 2025
- Pendulums
- De-Broglie wavelength of an electron orbiting in the \(n = 2\) state of hydrogen atom is close to (Given Bohr radius = 0.052 nm):
- NEET (UG) - 2025
- de broglie hypothesis
- The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant \(K_1\) and \(K_2\) with thickness \(d/2\) and \(d/2\) respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. If \(K_1 = 1.25 K_2\), the value of \(K_2\) is :
- NEET (UG) - 2025
- Capacitors and Capacitance
- A wire of resistance \(R\) is cut into 8 equal pieces. From these pieces, two equivalent resistances are made by adding four of these together in parallel. Then these two are added in series. The net effective resistance of the combination is:
- NEET (UG) - 2025
- Resistance
Concepts Used:
Conductance
What is conductance?
Conductance is an expression of the ease with which electric current flows through materials like metals and nonmetals. In equations, an uppercase letter G symbolizes conductance. The standard unit of conductance is siemens (S), formerly known as mho.
What is conductance in electricity?
Conductance in electricity is considered the opposite of resistance (R). Resistance is essentially the amount of friction a component presents to the flow of current.
The conductivity of electrolytic solutions is governed by the following factors:
- Interionic attraction
- Solvation of ions
- The viscosity of the solvent
- Temperature