Electrochemistry class 12th presentation

Electrochemistry

1. Chemistry Class- 3 Physical Chemistry Chapter- ELECTROCHEMISTRY By Chahek Maam

2. Conductivity in solids

3. Electrochemical cells Electrolytic cells Galvanic cells Non- spontaneous reaction ∆ G = +ive Conversion of Electrical energy to Chemical energy Spontaneous reaction ∆ G = -ive Conversion of Chemical energy to electrical energy

4. Electrolytic Cells and Electrolysis Electrolysis- It is defined as a process of decomposition of an electrolyte by the passage of electricity through its aqueous solution or molten state. The apparatus used to bring about electrolysis is called electrolytic cell. It consists of a glass vessel in which the electrolyte is in the form of an aqueous solution or in molten state. Two rods are dipped into it and are connected to a source of electricity. Conductivity in liquids

5. Galvanic cells(voltaic cells ) A device used to convert chemical energy produced in a redox reaction into electrical energy is called a galvanic cell or voltaic cell. The reaction is spontaneous. Redox reaction between Zn and CuSO 4 : Zn(s) + CuSO 4 (aq) ZnSO 4 (aq) + Cu(s) Zn(s)+Cu 2+ (aq) Zn 2+ (aq) + Cu(s) This reaction may be split into two half reactions as under: Zn Zn 2+ + 2e - (oxidation half reaction) Cu 2+ + 2e - Cu (reduction half reaction)

6. Salt bridge and its function. A salt bridge is a U-shaped tube containing concentrated solution of an inert electrolyte like KCl , KNO 3 , K 2 SO 4 etc. or solidified solution of such an electrolyte in agar-agar and gelatine. Inert electrolyte is one whose ions do not take part in the redox reaction and also do not react with electrolyte used. The main functions of salt bridge are- To complete the electrical circuit by allowing the ions to flow from one solution to the other without mixing of the two solutions. To maintain the electrical neutrality of the solutions in the two half-cells.

7. Difference between conductivity in solids and electrolytes

8. Q1. A cathode and an anode are the most common components of an electrochemical cell. Which of the following claims about the cathode is correct? Oxidation occurs at the cathode b) Electrons move into the cathode c) Usually denoted by a negative sign d) Is usually made up of insulating material

9. Q2. Which of the following statement is correct about Galvanic cell? It converts chemical energy into electrical energy. It converts electric energy into chemical energy It converts metal from its free state to the combined state. It converts electrolyte into individual ions.

10. Q3. The process of transmitting electric current through an electrolyte’s solution to decompose it is known as __________ Electrolyte b) Electrode c) Electrolysis d) Electrochemical cell

11. PRACTICE QUESTIONS

12. Electrolysis of Molten ionic compounds

13. Electrolysis of water

14. Q4. Molten sodium chloride conducts electricity due to presence of: Free electron Free ions Free molecules Atoms of sodium and chloride

15. Q5. In the electrolytic cell, flow of electrons is from Cathode to anode in the solution Cathode to anode through external supply Cathode to anode through internal supply Anode to cathode through external supply

16. Q6. The arrangement which converts chemical energy of a redox reaction into electrical energy is called_______ Electrochemical cell Electrolytic cell Fuel cell Half cell

17. HYDROGEN AS A FUEL CELL

18. PRACTICE QUESTIONS

19. TEST-30 marks Q5.Explain the major difference between electrical conductivity in metals and solutions in terms of the particles that are carrying the current. (2) Q6.

20. Q7. 50.0 kg of N 2  (g) and 10.0 kg of H 2  (g) are mixed to produce NH 3  (g). Identify the limiting reagent in the production of NH 3  in this situation. Also calculate the amount of NH3 obtained. (2) Q9. Define the following terms- (2) Electrolyte Titration Q8

21. THANK YOU