MHT CET202314 May 2023Morning ShiftChemistryElectrochemistryActual
Calculate molar conductivity of NH ₄ OH at infinite dilution if molar conductivities of Ba ( OH )₂ BaCl ₂ and NH ₄ Cl at infinite dilution are 520,280,129 ⁻¹ ~cm ^2 ~mol ⁻¹ respectively.
Options
- A249.0 ⁻¹ ~cm ^2 ~mol ⁻¹
- B498.0 ⁻¹ ~cm ^2 ~mol ⁻¹
- C125.0 ⁻¹ ~cm ^2 ~mol ⁻¹
- D369.0 ⁻¹ ~cm ^2 ~mol ⁻¹
Correct answer
A. 249.0 ⁻¹ ~cm ^2 ~mol ⁻¹
Step-by-step solution
According to Kohlrausch law, i. ₀ ( Ba ( OH )₂ )= _ Ba ²⁺ ^0+2 _ OH ⁻ ^0 ii. ₀ ( BaCl ₂ )= _ Ba ²⁺ ^0+2 _ Cl ⁻ ^0 iii. ₀ ( NH ₄ Cl )= _ NH ₄⁺ ^0+ _ Cl ⁻ ^0 Eq ( i )+ 1 2 Eq (ii) - 1 2 Eq (iii) gives aligned ₀ ( NH ₄ OH )= ₀ ( NH ₄ Cl )+ & 1 2 ₀ ( Ba ( OH )₂ ) & - 1 2 ₀ ( BaCl ₂ ) aligned ₀ ( NH ₄ OH )=129+ 1 2 520- 1 2 280=249.0 ⁻¹ ~cm ^2 ~mol ⁻¹