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Molar conductivity from resistance or resistivity and concentration

This type of question, asked 5 times: 2021 Paper 21, 29 Jul 2022, 31 Jan 2023, 2 Apr 2025, 5 Apr 2026 S2. All 5 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    2021 Paper 21

    56
    The resistance of a conductivity cell with cell constant 1.14 cm−11.14\text{ }cm^{- 1}, containing 0.001 M KCl0.001\text{ }M\text{ }KCl at 298 K298\text{ }K is 1500 Ω1500\ \Omega. The molar conductivity of 0.001 M KCl0.001\text{ }M\text{ }KCl solution at 298 K298\text{ }K in S cm2 mol−1S\text{ }cm^{2}\text{ }mol^{- 1} is (Integer answer)

  2. Question 2

    29 Jul 2022

    51
    Resistance of a conductivity cell (cell constant 129 m−1129{\text{ }m}^{- 1} ) filled with 74.5ppm74.5ppm solution of KClKCl is 100Ω100\Omega (labelled as solution 1). When the same cell is filled with KClKCl solution of 149ppm149ppm, the resistance is 50Ω50\Omega (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. ∧1∧2=x×10−3\frac{\land_{1}}{\land_{2}}= x \times10^{- 3}. The value of xx is______(Nearest integer) Given, molar mass of KClKCl is 74.5 g mol−174.5\text{ }g{\text{ }mol}^{- 1}

  3. Question 3

    31 Jan 2023

    144
    The resistivity of a 0.8M0.8M solution of an electrolyte is 5×10−3Ωcm5 \times10^{- 3}\Omega cm. Its molar conductivity is ____×104Ω−1 cm2 mol−1\_\_\_\_\times10^{4}\Omega^{- 1}{\text{ }cm}^{2}{\text{ }mol}^{- 1}(Nearest integer)

  4. Question 4

    2 Apr 2025

    122
    0.2%(w/v)0.2\%(w/v) solution of NaOH is measured to have resistivity 870.0 mΩ m870.0\text{ }m\Omega\text{ }m. The molar conductivity of the solution will be ____\_\_\_\_ ×102 mS dm2 mol−1\times 10^{2}\ mS\ dm^{2}\ mol^{-1}. (Nearest integer)

  5. Question 5

    5 Apr 2026 S2

    49
    At 298 K , the molar conductivity of x%(w/w)x\%(w/w) MX solution (aqueous) is 123.5 S cm2 mol−1123.5\text{ }S{\text{ }cm}^{2}{\text{ }mol}^{- 1}. The conductance of same solution is 1.9×10−3 S1.9 \times 10^{- 3}\text{ }S. The value of xx is ____\_\_\_\_ ×10−2\times 10^{- 2}. (Given : cell constant =1.3 cm−1= 1.3{\text{ }cm}^{- 1}; molar mass of MX is 75 g mol−175\text{ }g{\text{ }mol}^{- 1}, density of aqueous solution of MX at 298 K is 1.0 g mL−11.0\text{ }g{\text{ }mL}^{- 1} )