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Conductometry

Equivalence point is not equal to end point. 

Learn structures of phenolphthalein and methyl orange. 

phenolphthalein 

  • Colorless in acid 

  • Pink in base 

CONDUCTOMETRY 

Conductance: the flow of electrons,  ions or both through that material. Wherever the flow is high, more conductance 

Inversely proportional to resistance 

Can be classified into three types 

  1. Specific conductance/conductivity: the conductance of a solution or a material when kept between two similar electrodes each having a surface area of 1cm^2 and separated by a distance of 1 cm. It is denoted by the green letter kappa 

  2. Equivalent conductance: conductance of a solution containing 1 eq. ions and placed between “two similar electrodes…”. Denoted by the Greek letter lambda 

  3. Molar conductance: “… containing” 1 mol of ions. 

Lambda= kappa/ eq. concentration.  https://youtu.be/Wz1GgMJM5dU

Conductors 

1st kind: due to flow of electrons 

2nd kind: due to flow of ions.  

  • More the ions more will be the specific conductance. 

  • More the concentration of ions less is the equivalent conductance 

  • Ionic conductance of h+ ion is highest and ionic conductance of OH- is 2nd highest due to quantum tunneling effect. 

Debye heckle theory of conductance  

  1. In a solution each ion is surrounded by oppositely charged ions in a spherical manner. 

  2. The ion at the center is called the central ion whereas the surrounding oppositely charged ions are known as ionic cloud or ionic atmosphere  

  3. The central ion may be a part of some other ionic cloud. 

  4. The movement of the central ion and the ionic cloud is governed by electrostatic attractions and repulsions