This method employs an electric current to deposit a solid on an electrode from a solution. Normally the deposit is a metallic plate that has formed from the corresponding metallic ions in the solution; however, other electrode coatings also can be formed. The use…. Electrogravimetry was briefly described above as an interference removal technique.
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Submit Search. Successfully reported this slideshow. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime. Upcoming SlideShare. Like this presentation? Why not share! Embed Size px. Start on. Show related SlideShares at end.
WordPress Shortcode. AkshayAkotkar Follow. Published in: Science. Full Name Comment goes here. Are you sure you want to Yes No. Show More. No Downloads. Views Total views. Actions Shares. Embeds 0 No embeds. No notes for slide. Presented By : Mr. Akshay M. Akotkar B. Pharm IV th yr 2. Electrogravimetric analysis is more or less similar to conventional gravimetric analysis.
However in electrogravimetry the product is deposited quantitatively on an electrode by an electrolytic reaction and the amount of the product is determined by weighing the electrode before and after electrolysis.
The material is deposited on an electrode by the application of a potential instead of chemical precipitation from a solution. Hence the name electrogravimetry weighing of the product after electrolysis.
Composed by: Khalid, M 44, M. There are two types of electrogravimetric methods i Constant current electrolysis and ii Constant potential electrolysis. Constant Current Electrolysis- Herein electrodeposition is carried out by keeping the current constant. Here periodic increases in the applied potential are required adjust the potential of the cell as the electrolysis proceeds. A 6 V storage battery can be used for DC power source.
An ammeter and voltmeter are used to indicate the current and applied voltage respectively. The voltage applied to the cell is controlled by a resistor. The cathode is usually a cylindrical platinum gauze.
Apparatus for constant current electrolysis 9. Constant Potential Electrolysis- By controlled potential electrolysis, it is possible to separate two elements whose deposition potentials differ sufficiently by a few tenths of a volt.
The potential of the cathode is controlled so that it never becomes sufficiently negative to allow the deposition of the next element. As can be seen from the the potential of the cathode becomes negative due to concentration polarisation and that co-deposition of the other species begins before the analyte is completely deposited. Apparatus for controlled-potential electrolysis. Contact C is adjusted as necessary to maintain the working electrode cathode in this example at a constant potential.
The current in the reference-electrode circuit is essentially zero at all times Separation 3. Preconcentration 4. You just clipped your first slide! Clipping is a handy way to collect important slides you want to go back to later. Now customize the name of a clipboard to store your clips. Visibility Others can see my Clipboard. Cancel Save.
7.2: Electrodeposition (Electrogravimetry)
Electrogravimetry is a method used to separate and quantify ions of a substance, usually a metal. In this process, the analyte solution is electrolyzed. Electrochemical reduction causes the analyte to be deposited on the cathode. The mass of the cathode is determined before and after the experiment, and the difference is used to calculate the mass of analyte in the original solution. Controlling the potential of the electrode is important to ensure that only the metal being analyzed will be deposited on the electrode. The process is similar to electroplating.