CBSE Class 12 Chemistry 2024: question 22
Set in the CBSE Class 12 board exam of 2024, paper 56/1/1, section C, question 22, for 3 marks. Try it first; the hints and our step-by-step solution are below.
Q22 · 3 marks · Short answerElectrochemistry
When a certain conductivity cell was filled with 0·05 M KCl solution, it has a resistance of 100 ohm at 25ºC. When the same cell was filled with 0·02 M solution, the resistance was 90 ohm. Calculate the conductivity and molar conductivity of solution.
(Given : Conductivity of 0·05 M KCl solution = )
Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 56/1/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
The cell constant is the same for both solutions — find it using KCl.
Hint 2
Then use κ = G*/R and Λm = κ×1000/C.
Step-by-step solution
Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.
- 1 mark
Cell constant from KCl:
- 1 mark
Conductivity of AgNO₃:
- 1 mark
Molar conductivity:
Answer: κ = 0.015 S cm⁻¹; Λm = 750 S cm² mol⁻¹
Where the marks are
- Cell constant = 1.35 cm⁻¹ (1 mark)
- Conductivity of AgNO₃ = 0.015 S cm⁻¹ (1 mark)
- Molar conductivity = 750 S cm² mol⁻¹ with unit (1 mark; ½ deducted for missing/wrong unit)
Revise the chapter
- Chapter: Electrochemistry (notes, formulas, where marks are lost and every past question)
- Topic: Conductivity, Molar Conductivity and Kohlrausch's Law
More questions from Electrochemistry
- 2024 board paper, set 56/1/1, Q29 · 4 marksBatteries and fuel cells are very useful forms of galvanic cell. Any battery or cell that we use as a source o…
- 2024 board paper, set 56/5/1, Q11 · 1 markDilution affects both conductivity as well as molar conductivity. Effect of dilution on both is as follows :
- 2024 board paper, set 56/5/1, Q17 · 2 marksState :
The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.