0.2% (w/v) solution of NaOH is measured to have resistivity 870.0 mΩ m. The molar conductivity of the solution will be ______ ×102 mS dm2 mol-1. (Nearest integer) [2025]
(23)
Molarity of NaOH (C)=(%w/v)×10MNaOH
=0.2×1040=0.05M
ρ=870 mΩ m=870×10-3 Ω×100 cm=87 Ω cm
κ=1ρ=187 S cm-1
Λm=1000κCS cm2 mol-1
=100087×0.05S cm2 mol-1=229.885 S cm2 mol-1
=229.885×1000mS (10-1 dm)2 mol-1
=22.99×102 mS dm2 mol-1