NEET2026ChemistryChapterActual
A conductivity cell filled with 0.1 M HCl solution has a resistance of 50 at 300 K . If the conductivity of 0.1 M HCl is 3.6 10⁻² S cm ⁻¹ , what will be the conductivity of a 0.02 M NaCl solution if the same cell filled with it offers a resistance of 400 at the same temperature?
Options
- A7.2 10⁻³ S cm ⁻¹
- B4.5 10⁻³ S cm ⁻¹
- C2.5 10⁻³ S cm ⁻¹
- D1.8 10⁻³ S cm ⁻¹
Correct answer
B. 4.5 10⁻³ S cm ⁻¹
Step-by-step solution
The cell constant G^ * is given by the product of conductivity and resistance R . For the 0.1 M HCl solution: G^ * = ₁ R₁ G^ * = 3.6 10⁻² S cm ⁻¹ 50 = 1.8 cm ⁻¹ Since the same conductivity cell is used, the cell constant remains the same. For the 0.02 M NaCl solution: ₂ = G^ * R₂ ₂ = 1.8 cm ⁻¹ 400 = 4.5 10⁻³ S cm ⁻¹ Answer: 4.5 10⁻³ S cm ⁻¹