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Electrochemistry · Question 32

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1

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

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2

For a Mg | Mg2+(aq) || Ag+(aq) | Ag the correct Nernst Equation is :

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3

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  1. Molar conductivity increases sharply with increase in concentration.
  2. Molar conductivity decreases sharply with increase in concentration.
  3. A small increase in molar conductivity is observed at infinite dilution.
  4. A small decrease in molar conductivity is observed at infinite dilution.
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