Question

Describe the alternating current methods in voltammetry.

06 Apr 2018
Answer :
Word Count : 781

Alternative current (AC) voltammetry is an accurate electroanalysis method and combination with preconcentration will enhance the sensitivities of this analytical techniques. AC Voltammetry generally involves in the application of a sinusodially oscillating voltage to an electrochemical cell. The AC experiment is used in conjunction with a fixed amplifier or frequency analyser which will increase sensitivity considerably over the early described techniques. AC voltammetry can also reveal the important of mechanistic and kinetic information which is not easily available when using the tradition voltammetric techniques.

Measurement of AC voltammetric is usually used in an electrochemical cell and the dominate mode of transport is diffusion. A steady DC signal or voltage sweep will often combined with the AC voltage.

The following figure shows a cyclic voltammetric signal with an AC perturbation.

Image ignouacademy-com--p-methods-92009

Alternating potential usually has a frequency of 50-100Hz and 10-20mV amplitude. The AC signal causes a perturbation in the surface concentration and DC potential ramp maintained the concentration. The resulting AC current is plotted against the potential. For example, voltammogram appears a peak, the potential of which is the same as the polarographic half-wave potential. At this region, the sinusoid has maximum impact on the surface concentration like on the current.

Image ignouacademy-com--p-ignou-60192

For a reversible system, such a response is actually the derivative

_________ ______ ________ _________ ______.
__________ __________ _______ ___ __________ ________ ______ _____ _____.
______ ________ ______ __________ _______ ______ __________ ______ ____ _____ ________ _____.
_______ _______ ____ __________ _______ ________ _______ ___ ____.
_______ ______ _________ _________ _________ ______ __________ __________ _________ ________ _________.
_______ _______ ___ _________ _______ ____ __________ ______.
__________ ______ _________ _________ __________ _______ ____.
______ ____ __________ ____ _______ ____.
____ ______ ____ _____ ____ ____ ____ ___ ________.
_______ ____ ________ ____ _____ ______ ________.
______ __________ _______ ________ ___ ___ _____.
________ __________ _______ __________ __________ ________ ______ ______ ___ __________ ____.
___ _______ ________ ____ _________ _____ ___ ______ _____.
______ _____ ____ ____ _______ _________ ______ _____ ________ ________.
_____ __________ ______ _______ ____ ____ __________ ________.
______ _______ ______ ____ _____ _____ _____ ______.
____ __________ ____ _______ ______ _______ ___.
___ _________ ________ ______ __________ _________ ________ __________ ___ _______.
_______ _________ _____ ___ ________ _________ __________ _____.
________ _______ ___ ___ ______ _______ ____.
________ _______ ___ _______ ____ _______ _______ ________ _________.
_____ __________ ___ ____ _____ _______.
________ ___ ________ ____ ____ ____ ______ _________ _________.
_____ _____ _______ ____ __________.
_____ ______ ___ _____ ______ _______ ____ _______.
___ __________ ___ ___ _________ _____ __________.
_____ ___ ____ __________ _____ __________ _______ __________.
_______ __________ ________ ____ _________ _____ ____ __________ ______ _______ ___ ________.
______ ____ __________ __________ __________ _______ __________ _______ ________ ________.
______ ________ ____ ______ ____.
_______ ____ _________ ________ ______ ____ _______ ___ ___ _________.
____ __________ _____ ______ _______.
___ _________ __________ ________ _______ __________ __________ _______ _______.
_______ ___ _________ _______ _____ _________ ________ ____ ___ _____.
___ _______ ___ ______ _________ _____ ______ ___ __________ _______ ________.
_______ ______ ______ _____ _______ ________.
___ _____ _______ ___ ________ __________ _____.
______ _______ ______ __________ _______ _____ ______ ______ _____ ______ ___ ____.
___ _________ __________ ________ ____ ________ _____ _____.
____ ___ _____ ___ _________.
____ _______ ________ ____ ______ __________ __________ __________ ______ __________ ______ _________.
___ ___ __________ ___ ____ _____ ____ ___.
__________ __________ _____ ________ ___ _______ _____ _____ ____ _____ ____ __________.
___ ______ _____ ___ ________ ________ _____ ___ _________ __________ _____ ________.
_____ _________ ____ ______ ____ ____.
______ ____ ________ ________ __________ ____ __________ ________ ________ _________ ___ ___.
__________ __________ _________ ___ ________ _______ __________ ____ _____ ____ ______.
__________ ___ __________ ___ ___ _______ _____ ____ __________ __________ ____.
__________ _________ ________ ______ _________ _________ _______.
_______ _________ ________ _____ _____ _____ _________ _____ ___.
__________ _________ ___ ___ ______.
____ ____ ____ ___ __________ ________ ______ __________ ________ ________ _________ ______.
______ _________ _______ _______ _____ _____ _________ _____ ____ ____.
__________ __________ _______ __________ _______ __________ _____ _____ ________ _____.
__________ _________ _______ _________ _________.
____ ____ ___ _____ _____ ___ ________ _____ _______.
______ _______ ____ ___ ____ ______.
_____ _________ _______ _____ ______ ___ ______ ___ __________ _________.
_______ __________ __________ __________ _______ ______ _______ ___ ________.
_______ _______ __________ __________ _____ _________.
_________ _____ _________ ___ ________ __________ _________ _____ _________ _____.
________ ________ __________ ___ ________ _________ _________ ____ ____.
______ ____ ___ __________ _____ ______ ____ _____ _______ __________ ______ _________.
______ __________ _______ _________ ________ ___.
___ ____ ______ ____ __________ ___ __________ ______.
____ ______ ______ ____ ____.
IGNOU ACADEMY
Your IGNOU journey, made easier.
  • Solved Assignments
  • Study Notes
  • Guess Papers
  • Question Papers
Call Us WhatsApp
STUDY • PREPARE • SUCCEED
Skip in 10
Related Questions

What are the advantages of DTA and DSC over TGA?

How the conductance is varies with concentration? Explain with the help of suitable examples.

Discuss the factors which limit the accuracy of pH measurements.

Given the following reaction half reaction:

Cd2+ + 2e ® Cd    E° = - 0.403 V

Pb2+ + 2e-®Pb     E° = - 0.126 V

where [Cd2+] = 0.020 M and [Pb2+] = 0.200 M

construct a galvanic cell using half cell reactions and find

i) Which half cell –reaction is the cathode?

ii) Write the cell reaction.

iii) Calculate E_{cell}^{\circ} of this galvanic cell.

iv) Calculate Ecell of this galvanic cell

v) Calculate equilibrium constant using E°cell potentials of this galvanic cell based on the construction of ions.

An impure sample of CaC2O4H2O is analysed using TGA technique. TG curve of the sample indicates the total mass change from 85 mg to 30.7 mg when this sample was heated upto 1173 K. calculate the purity of the sample.

At 291 K, the conductivity of pure water is 4.3 ´ 10-6 S m-1. Calculate the ionic product of pure water at 291 K.

Hint: Consult Table 4.2 for the limiting ionic conductivity of H+ and OH- ions.

Discuss the methodology of radio immune essay and list its advantages.

IGNOU Solved Assignments Assignments Ignou Projects Project Previous Year Solved Exam Papers Notes Notes Sample Question Papers Sample Question Papers
Login
Top
📞
Call Support Instant phone assistance IGNOU MCH 4 2018 - Describe the alternating current methods in voltammetry. | IGNOU Academy
→
🟢
WhatsApp Chat Fast live messaging
→
Email Us Business enquiries & support
→