A conductivity cell with cell constant $1.20 c m^{- 1}$ is filled with a $0.050 M$ solution of a strong 1:1 electrolyte AB. The measured resistance is $300 Ω$ . Which of the following statement(s) is/are correct?

AThe conductivity of the solution is $4.0 \times 1 0^{- 3} S c m^{- 1}$
BThe molar conductivity of the solution is $80 S c m^{2} mo l^{- 1}$
CIf the same cell is filled with $0.100 M$ AB, the resistance will be exactly $150 Ω$
DThe molar conductivity of the solution in SI units is $8.0 \times 1 0^{- 3} S m^{2} mo l^{- 1}$

Answer: A, B, D

κ = G^{*} / R = 1.20/300 = 4.0 \times 1 0^{- 3} S c m^{- 1}

, so (A) is correct.

Λ_{m} = 1000 κ / c = 1000 \times 4.0 \times 1 0^{- 3} /0.050 = 80 S c m^{2} mo l^{- 1}

, so (B) is correct. Since

1 c m^{2} = 1 0^{- 4} m^{2}

Λ_{m} = 80 \times 1 0^{- 4} = 8.0 \times 1 0^{- 3} S m^{2} mo l^{- 1}

, so (D) is correct. (C) is wrong:

Λ_{m}

of a strong electrolyte decreases with concentration, so

κ

at 0.100 M is less than double and the resistance is somewhat more than

150 Ω