English

Why Conductivity of an Electrolyte Solution Decreases with the Decrease in Concentration ? - Chemistry

Advertisements
Advertisements

Question

Why conductivity of an electrolyte solution decreases with the decrease in concentration ?

Advertisements

Solution

The conductivity of an electrolyte solution is the conductance of ions present in a unit volume of the solution. The number of ions (responsible for carrying current) decreases when the solution is diluted or the concentration is decreased. As a result, the conductivity of an electrolyte solution decreases with the decrease in concentration.

shaalaa.com
  Is there an error in this question or solution?
2014-2015 (March) Delhi Set 3

RELATED QUESTIONS

Define limiting molar conductivity.


The conductivity of 0.20 mol L−1 solution of KCl is 2.48 × 10−2 S cm−1. Calculate its molar conductivity and degree of dissociation (α). Given λ0 (K+) = 73.5 S cm2 mol−1 and λ0 (C1) = 76.5 S cm2 mol−1.


Why does the conductivity of a solution decrease with dilution?


10.0 grams of caustic soda when dissolved in 250 cm3 of water, the resultant gram molarity of solution is _______.

(A) 0.25 M

(B) 0.5 M

(C) 1.0 M

(D) 0.1 M


In the plot of molar conductivity (∧m) vs square root of concentration (c1/2), following curves are obtained for two electrolytes A and B:

Answer the following:
(i) Predict the nature of electrolytes A and B.
(ii) What happens on extrapolation of ∧m to concentration approaching zero for electrolytes A and B?


Assertion: Copper sulphate can be stored in zinc vessel.

Reason: Zinc is less reactive than copper.


The variation of molar conductivity with concentration of an electrolyte (X) m aqueous solution is shown in the given figure.

The electrolyte X is ______.


The following questions are case-based questions. Read the passage carefully and answer the questions that follow:

Rahul set up an experiment to find the resistance of aqueous KCl solution for different concentrations at 298 K using a conductivity cell connected to a Wheatstone bridge. He fed the Wheatstone bridge with a.c. power in the audio frequency range 550 to 5000 cycles per second. Once the resistance was calculated from the null point, he also calculated the conductivity K and molar conductivity ∧m and recorded his readings in tabular form.
S. No. Conc.
(M)
k S cm−1 m S cm2 mol−1
1. 1.00 111.3 × 10−3 111.3
2. 0.10 12.9 × 10−3 129.0
3. 0.01 1.41 × 10−3 141.0

Answer the following questions:

(a) Why does conductivity decrease with dilution? (1)

(b) If `∧_"m"^0` of KCl is 150.0 S cm2 mol−1, calculate the degree of dissociation of 0.01 M KCI. (1)

(c) If Rahul had used HCl instead of KCl then would you expect the ∧m values to be more or less than those per KCl for a given concentration? Justify. (2)

OR

(c) Amit a classmate of Rahul repeated the same experiment with CH3COOH solution instead of KCl solution. Give one point that would be similar and one that would be different in his observations as compared to Rahul. (2)


Which of the following solutions will have the highest conductivity at 298 K? 


The specific conductance of 2.5 × 10-4 M formic acid is 5.25 × 10-5 ohm-1 cm-1. Calculate its molar conductivity and degree of dissociation.

Given `λ°_("H"^+)` = 349.5 ohm-1 cm2 mol-1 and

`λ°_("HCOO"^-)  = 50.5 " ohm"^-1 "cm"^2  "mol"^-1`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×