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प्रश्न
Write a note on sacrificial protection.
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उत्तर
In this method, the metallic structure to be protected is made cathode by connecting it with more active metal (anodic metal). So that all the corrosion will concentrate only on the active metal. The artificially made anode thus gradually gets corroded protecting the original metallic structure. Hence this process is otherwise known as sacrificial anodic protection. Al, Zn and Mg are used as sacrificial anodes.
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संबंधित प्रश्न
Among Zn and Cu, which would occur more readily in nature as metal and which as an ion?
How many faradays of electricity are required to produce 6 g of Mg from MgCl2?
A solution of Cu(NO3)2 is electrolyzed between platinum electrodes using 0.1 Faraday electricity. How many moles of Cu will be deposited at the cathode?
If one mole electrons is passed through the solutions of CrCl3, AgNO3 and NiSO4, in what ratio Cr, Ag and Ni will be deposited at the electrodes?
Two metals M1 and M2 have reduction potential values of −xV and +yV respectively. Which will liberate H2 and H2SO4.
`E_(cell)^Θ` for some half cell reactions are given below. On the basis of these mark the correct answer.
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(b) \[\ce{2H2O (1) -> O2 (g) + 4H^{+} (aq) + 4e^{-}; E^Θ_{cell} = 1.23V}\]
(c) \[\ce{2SO^{2-}_{4} (aq) -> S2O^{2-}_{8} (aq) + 2e^{-}; E^Θ_{cell} = 1.96V}\]
(i) In dilute sulphuric acid solution, hydrogen will be reduced at cathode.
(ii) In concentrated sulphuric acid solution, water will be oxidised at anode.
(iii) In dilute sulphuric acid solution, water will be oxidised at anode.
(iv) In dilute sulphuric acid solution, \[\ce{SO4^{2-}}\] ion will be oxidised to tetrathionate ion at anode.
`E_(cell)^Θ` = 1.1V for Daniel cell. Which of the following expressions are correct description of state of equilibrium in this cell?
(i) 1.1 = `K_c`
(ii) `(2.303RT)/(2F) logK_c` = 1.1
(iii) `log K_c = 2.2/0.059`
(iv) `log K_c` = 1.1
The electrochemical cell stops working after some time because
Galvanic cell is a device in which ______.
State the term for the following:
Two metal plates or wires through which the current enters and leaves the electrolytic cell.
