- More Questions...
- Write a note on Glass Electrode
1842 Views
- What are the advantages of D.M.E. over the other electrodes OR write note on D.M.E.
1632 Views
- Describe the construction and working of manual Polarography?
1645 Views
- Describe the Polarographic technique using H shaped Polarographic cell?
1595 Views
By Sunil Bhardwaj
2724 Views
In 1922, Heyrovsky, discovered a technique with the help of which, qualitative, quantitative and even mixture can be analyzed qualitatively and quantitatively, the technique is known as Polarography. In this case electrolysis of experimental solution is done. The cathode is polarized electrode (where deposition takes place) and anode is non polarized electrode.
In Polarography we plot a graph of current in \(\mu A\) V/s potential applied in volts. The graph obtained is known as Polarogram. It is S shaped wave. The Polarogram is divided into three portions.
Residual current \((i_R)\): The current which is associated with the impurities is known as Residual current. AB portion of the graph corresponds to residual current \(i_R\)
Diffusion current \((i_d)\): At the point B, the potential applied is equal to reduction potential of metal ions. The metal gets reduced over DME and current is produced.$$ { M }^{ n+ }+{ ne }^{ - }\longrightarrow { M } $$ $$ { M }+{ Hg }\longrightarrow { M(Hg) } $$ As large amount of metal ions are reduced, so the current will increase rapidly. At the point C reduction is complete.$$ i_d = i_L - i_R $$
Limiting Current \((i_L)\): At the point C, all the metallic ions are reduced. As no more metallic ions, so no further increase of current and now the current remain constant. This constant current is known as Limiting current.
Half wave potential \(({ E }_{ 1/2 })\): The half wave potential is defined as that potential at which half of the total metal ions present in the electrolyte are reduced. OR when \(i= id/2\) then, \(E = { E }_{ 1/2 }\)
- Explain how can you have quantitative analysis by Polarography?
3177 Views
- State the Ilkovic Equation and explain the terms involved.
1772 Views
- Define and derive an expression for half wave potential? OR Write note in Half wave potential?
1107 Views
- Why N2 gas is bubbled through experimental solution in Polarography?
1399 Views
- What is a Hump OR maximum in Polarographic wave and how it can be eliminated?
1877 Views
- More Questions...
Prof. Gianfranco Coletti
Shared publicly - 2019-08-23 00:00:00
Don’t want your columns to simply stack in some grid tiers? Use a combination of different classes for each tier as needed. See the example below for a better idea of how it all works.
Prof. Maheshwar Sharon
Shared publicly - 2019-08-24 00:00:00
For grids that are the same from the smallest of devices to the largest, use the .col and .col-* classes. Specify a numbered class when you need a particularly sized column; otherwise, feel free to stick to
sunil
Shared publicly - 2023-02-28 11:09:52
this is
ss
Shared publicly - 2023-02-28 10:48:10
gsgsg
Latest News
-
Become an Instructor
4 March, 2018
Apply to join the passionate instructors who share their expertise and knowledge with the world. You'll collaborate with some of the industry's best producers, directors, and editors so that your content is presented in the best possible light..