0.2\% (w/v) solution of NaOH is measured to have resistivity 870.0 m m. The molar conductivity of the solution will be 102 mS dm2 mol-1. (Nearest integer)
Answer
23
Solution
0.2\% (w/v) 0.2 g NaOH in 100 mL 2 g NaOH per litre
c = 240 = 0.05 mol L-1 = 50 mol m-3
= 870.0 m m = 0.870 m
= 1 = 10.870 = 1.149 S m-1
m = c = 1.14950 = 2.299 10-2 S m2 mol-1
1 S m2 = 103 mS 102 dm2 = 105 mS dm2
m = 2.299 103 mS dm2 mol-1
= 22.99 102 23 102 mS dm2 mol-1
Answer: 23