Course Content
CHAPTER 10: HALOALKANES AND HALOARENES
Topic Name 10 Haloalkanes and Haloarenes 10.1 Classification 10.2 Nomenclature 10.3 Nature of C–X Bond 10.4 Methods of Preparation of Haloalkanes 10.5 Preparation of Haloarenes 10.6 Physical Properties 10.7 Chemical Reactions
0/4
CHAPTER 11: ALCOHOLS, PHENOLS AND ETHERS
Topic Name 11 Alcohols, Phenols and Ethers 11.1 Classification 11.2 Nomenclature 11.3 Structures of Functional Groups 11.4 Alcohols and Phenols 11.5 Some Commercially Important Alcohols 11.6 Ethers
0/3
CHAPTER 13: AMINES
Topic Name 13 Amines 13.1 Structure of Amines 13.2 Classification 13.3 Nomenclature 13.4 Preparation of Amines 13.5 Physical Properties 13.6 Chemical Reactions 13.7 Method of Preparation of Diazonium Salts 13.8 Physical Properties 13.9 Chemical Reactions 13.10 Importance of Diazonium Salts in Synthesis of Aromatic Compounds
0/3
CHAPTER 14: BIOMOLECULES
Topic Name 14 Biomolecules 14.1 Carbohydrates 14.2 Proteins 14.3 Enzymes 14.4 Vitamins 14.5 Nucleic Acids 14.6 Hormones
0/3
CHAPTER 15: POLYMERS
Topic Name 15 Polymers 15.1 Classification of Polymers 15.2 Types of Polymerisation Reactions 15.3 Molecular Mass of Polymers 15.4 Biodegradable Polymers 15.5 Polymers of Commercial Importance
0/3
CHAPTER 16: CHEMISTRY IN EVERYDAY LIFE
Topic Name 16 Chemistry in Everyday Life 16.1 Drugs and their Classification 16.2 Drug-Target Interaction 16.3 Therapeutic Action of Different Classes of Drugs 16.4 Chemicals in Food 16.5 Cleansing Agents
0/3
Class 12th Chemistry Online Class: Excelling in CBSE Board Exams
About Lesson

Arrangement for measurement of Resistance

Class 12 Electrochemistry Notes
  • The arrangement consists of two resistances R3 and R4.
  • There is a variable resistance R1 and a conductivity cell with unknown resistance R2.
  • The Wheatstone bridge is provided with an oscillator O that acts as source of a.c. power.
  • The arrangement has a suitable detector P.
  • The Wheatstone bridge is balanced when there is no flow of current through the detector.

Unknown resistance = R2 = R1R4 /R3

  • After calculating the resistance the conductiviry can be easily calculated using the formula:
  • κ = G’ /R

Molar conductivity

  • It is denoted by the symbolIt is related to the conductivity of the solution by the following equation:
Class 12 Electrochemistry Notes
  • The units of is S mmol-1.

Problem:

THE CONDUCTIVITY OF 0.20 M SOLUTION OF KCL AT 298 K IS 0.0248 SCM-1. CALCULATE ITS MOLAR CONDUCTIVITY.

Solution:

k = 0.0248 S cm – 1

c = 0.20 M

Molar conductivity,Λm =  (k x 1000) / c

= 0.0248 x1000 / 0.20

= 124 Scmmol – 1

Variation of Conductivity and Molar Conductivity with Concentration

  • They depend on the concentration of the electrolyte. The Conductivity and Molar Conductivity of both weak and strong electrolytes decreases withdecrease in concentration as the number of ions per unitvolume carrying the current in a solution decreases on dilution.
  • Conductivity of a solution at a specific concentration = Conductance of solution placed in between the two platinum electrodes where
  • Volume of solution = 1 unit

 Cross sectional area of electrodes = 1unit

Class 12 Electrochemistry Notes
Wisdom TechSavvy Academy