Faraday's first law of electrolysis

this is a class 12 chemistry investigatory project on faraday's first law of electrolysis.

1. CHEMISTRY PROJECT - Verification of faraday’s 1 st law of electrolysis Made by - Sidharth Gund Class : 12 th – B Roll no. : 31

2. Index Certificate Acknowledgement Objective Theory Apparatus Material required Procedure Observation Calculations Result Bibliography

3. Certificate This is to certify that S idharth Gund of class 12 th – B , roll no.- 31 , of GREENWAY MODERN SR. SEC. SCHOOL has satisfactorily completed the project “verification of Faraday’s 1 st law of electrolysis” , under my guidance and supervision , issued by CBSE during session 2014 -2015 . ____________ Mrs. Nidhi Agnihotri (PGT , Chemistry) School Stamp

4. Acknowledgement :- It is my utmost pleasure to express my sincere gratitude t o my chemistry teacher Mrs. Nidhi Agnihotri without whose cooperation I would not have been able to complete my project. It was my privilege to work under her guidance and I heartily thank her for helping me through the course of my project. I am also grateful to Mrs. Manju Kasana who helped me in selecting the topic for my project. I would also like thank my parents for their valuable support

5. Objective :- “To verify Faraday’s 1 st law of electrolysis” ( The mass of an elements which is deposited on an electrode during electrolysis is directly proportional to the quantity of electricity which passes through the electrolyte .)

6. Theory :- Faraday's First Law of Electrolysis: Statement - The mass of an elements which is deposited on an electrode during electrolysis is directly proportional to the quantity of electricity which passes through the electrolyte. Explanation- If M is the amount of substance which liberates or deposited at the electrode on passing the electricity through the electrolyte and the quantity of electricity is Q, then

7. M α Q or M = ZQ Z is the electrochemical constant for a given substance. As , Q = i x t therefore , we can write the statement of the first law of electrolysis mathematically as under : M α i x t Or M= Zit If 1 ampere electric current passes through the electrolyte for 1 second then M=Zit means that on passing the current of 1 ampere ampere for 1 second the weight of the substance deposited is equal to the electrochemical constant.

8. Z is known as the electrochemical equivalent (E.C.E) of the substance. If q = 1C, then m = Z. unit of charge (Q) = Coulomb (C) unit of mass (m) = Kilogram (kg) unit of current (A) = ampere (A) unit of electrochemical equivalent (Z) = kg/C Apparatus :- Copper wires, copper plates, beakers, ammeter, rheostat, weighing machine, battery and a key . Materials Required :- Copper sulphate solution, Conc. H 2 SO 4 .

9. Procedure :- Prepare 500 ml copper sulphate solution and add a few drops of conc. H 2 SO 4 . Now, divide the copper sulphate solution into 3 beakers equally . Take 6 copper plates :- 3 as cathodes and 3 for anodes . Measure the weight of each cathode . Set up of the circuit – Connect 2 beakers in parallel with the third beaker with the help of copper electrodes and wires. Now, connect the battery, key, ammeter and rheostat .

10. Now, close the circuit, note down the reading in ammeter and leave the set up for 10 minutes. Now, close the circuit, note down the reading in ammeter and leave the set up for about 30 minutes. Switch off the circuit and weigh the cathodes again. Change the resistance with the help of rheostat and repeat the process one more time.

11. Observation :- Two cathodes are in parallel with one cathode therefore, current in the cathodes that are parallel will be less than the one in series According to Faraday’s law mass deposited on the parallel electrodes will be less than the mass deposited on the one in series.

12. Observation Table :- Time (in minutes) Mass of cathode * (in grams) Current (mili amperes) (Before) M1 (After) M2 (Mass deposited =M2-M1) M 1 st 2 nd 3 rd 1 st 2 nd 3 rd 1 st 2 nd 3 rd a. 30 300 b. 30 500 * Here 1 st cathode is the one in series and 2 nd and 3 rd are the ones in parallel

13. Calculations :- According to Faraday’s law – M= z it z=E/F E= equivalent mass (here of Cu2+ ion) = 63.546/2=31.773 F= Faraday’s constant =96500 z=31.773/(2x96500)=0.00016 Mass deposited on 1 st cathode= a. M=0.00016x 300 x(10^(-3))x30x60= 0.0864 g b. M=0.00016x 500 x(10^(-3))x30x60= 0.144 g

14. Mass deposited on 2 nd cathode= M=0.00016x 150 x(10^(-3))x30x60= 0.0432 g M=0.00016x 250 x(10^(-3))x30x60= 0.072 g Mass deposited on 3 rd cathode= M=0.00016x 150 x(10^(-3))x30x60= 0.0432 g M=0.00016x 250 x(10^(-3))x30x60= 0.072 g

15. Result According to Faraday’s law- Mass α charge or M=zit Mass deposited on cathodes is – Experimentally :- 1 st - a. _________g b. __________ g 2 nd - a._________g b.__________g 3 rd - a._________g b.__________g Theoretically :- 1 st - a. 0.0864 g b. 0.144 g 2 nd - a. 0.0432 g b. 0.072 g 3 rd - a. 0.0432 g b. 0.072 g

16. Experimental and theoretical values are equal and also mass deposited on 1 st cathode is more than the mass deposited on 2 nd and 3 rd cathode since, the current is more in 1 st cathode. Faraday’s first law of electrolysis is verified.

17. Bibliography The information about the project has been gathered from following – www.chemistrysubject.blogspot.in www.youtube.com