Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
The device through which chemical energy is converted into electrical energy is known as galvanic cell or electrochemical cell or voltaic cell. In a galvanic cell, a redox reaction is carried out in an indirect manner and the decrease in free energy process appears as electrical energy. An indirect redox reaction is such that reduction and oxidation processes are carried in separate vessels. In order to understand this phenomenon, let us consider the Zn - CuSO4 reaction as the basis of the cell reaction.
In its simple form, a zinc strip is dipped in the ZnSO4 solution and copper strip is dipped in the CuSO4 solution taken in separate beakers. The two metallic strips which act as electrodes are connected by the stripes conducting wires through a voltmeter. The two solutions are connected through a reversed U-tube known as salt bridge. The U-tube is filled with the solution of some electrolyte such KCl, KNO3 or NH4Cl to which gelatin or agar-agar has been added to convert it into semi-solid paste. A schematic of this cell has been shown. The deflection in voltmeter shows that there is a potential difference between the two electrodes. It has been establish that the conventional current flows from the outer circuit from copper to zinc strip. It means that the electrons flow occurs from zinc to copper strip. Let us now understand the working of the cell. (i) Zinc undergoes oxidization to form zinc ions Zn(s) Zn2+(aq) + 2e- (oxidization) (ii) The electrons liberated during oxidization are pushed through the connecting wires to copper strip. (iii) Copper ions move towards copper strip, pick up the electrons, and get reduced to copper atoms which hare deposited at the copper strip. (iv) Cu2+(aq) + 2e- Cu(s) (reduction) The electrode at which oxidization occurs is anode and that at which reduction occurs is cathode. In the above that, zinc strip is anode and the copper strip is cathode. Due to the oxidization process occurring at the anode it becomes a source of electrons and acquires a negative charge in the cell. Similarly, due to the reduction process occurring at the cathode it acquires positive charge and becomes a receiver of the electrons. Thus the electrochemical cell, anode electrode acts as negative terminal and cathode electrode acts as a positive terminal.
The magnetic quantum number for valency electrons of sodium is: (1) 3 (2) 2 (3) 1 (4) 0 Ans: 0
Chromium has the electronic configuration 4s 1 3d 5 rather than4s 2 , 3d 4 because: (1) 4s and 3d have the same energy (2) 4s has a higher energy than 3d (3)4s 1 is
what are the examples?
what are magnetism in d block?
Which has highest second ionisation energy? Electronic config of Na(+) is noble gas config. . so its very difficult to remove an electron so it will have very high 2nd ionisati
Prove that the number of orbitals in a principal quantum level is n^2 using the fact that the number of orbitals in a subshell is (2L-1) where L is the azimuthal quantum number.
Isoelectronic species are: (1) K + Cl - (2) Na + Cl - (3) Na Ar (4) Na + Ar Ans: K + Cl -
Liebermann's nitroso reaction While phenol is reacted with NaNO 2 and concentrated H 2 SO 4 , it provides a deep green or blue colour which changes to red on dilution with wa
Classification of proteins - Fibrous proteins These are composed of polypeptide chains which run parallel to the axis and are held together by a strong hydrogen and disulphide
write the structures of the major product (saytzeff elimination) when the following alcohols are dehydrated with hot,concentrated sulphuric acid. 1. 3-methyl-2-butanol 2. 2-pentano
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd