12th Grade Chemistry Project VARANASI PROJECT ON SESSION 2022 - 23 In successfully completing this project, many people have helped me. I would like to thank all those who are related to this project. Primarily, I would thank God for being able to complete this project with success. Then I will thank our Principal Mrs. Nirmala Rathore Ma’am and our teacher Mrs. Harjit Kaur Ma’am, under whose guidance I learned a lot about this project. Her suggestions and directions have helped in the completion of this project. Finally, I would like to thank my parents and friends who have helped me with their valuable suggestions and guidance and have been very helpful in various stages of project completion. CERTIFICATE This is to certify that MR. Rudra Pratap Singh A Students of Class XII-A Under the Board Roll No…………………………of GURU NANAK ENGLISH SCHOOL,SHIVPUR Has satisfactorily completed his CHEMISRY PROJECT FILE-043 During Academic Session 2022-2023. Under the guidance of Mrs. Harjit Mam Internal Examiner External Examiner Table of contents Sr. No. Topic 01 Introduction 02 Definition 03 Construction of Galvanic cell 04 Salt Bridge 05 Mechanism Of Galvanic cell 06 Representation of Galvanic cell 07 Daniell cell 08 09 Difference between Galvanic and Electrolytic cell Bibliography Introduction 01 Cells and batteries are unquestionably useful and important. Cells are used in so many various ways in our daily lives. A Galvanic Cell or Voltaic Cell is an electrochemical cell that exists alongside other cells. It converts the chemical energy of spontaneous redox reactions into electrical energy. A galvanic cell is an example of how energy can be collected through simple reactions between a few elements. In this article, we have discussed everything about galvanic cells including galvanic cell definition, Daniel cell and Leclanche cell . To facilitate balancing the overall equation for Galvanic cells and emphasizing the actual chemical transformations, it is often advantageous to divide the oxidationreduction reactions into half-reactions when formulating the equations. Read this article to know galvanic cell definition, construction and more. Definition 02 A device used to convert chemical energy produced in a redox reaction into electrical energy is called a galvanic cell. It is named after the name of scientist Luigi Galvani. Galvani cell is also called a voltaic cell, named after the scientist Alessandro Volta. Some common examples of galvanic cells are the Volta cell, Daniel cell, Leclanche cell, dry cell, etc. 03 Construction Of Galvanic Cell A galvanic cell is constructed by combining an oxidation electrode with a suitable reduction electrode to convert chemical energy into electrical energy by a redox reaction. Two electrolytic solutions, in which electrodes are immersed are connected to each through a porous diaphragm or a salt bridge. The two electrodes are connected to a device that utilizes the electrical energy produced in the outer circuit. Electrons get liberated i.e., oxidation occurs at the oxidation electrode. These electrons accumulate on the electrode and provide a negative potential. At the reduction electrode, a positive potential develops on account of the reduction process occurring at it. When these two electrodes are connected, electrons start flowing from the oxidation electrode to the reduction electrode in the outer circuit due to a difference in potential between them. Thus, an electric current is produced. The electrode at which the oxidation process occurs is called the anode, while the one at which the reduction process takes place is called the cathode. In a galvanic cell, the anode has a negative polarity and the cathode has a positive polarity. Salt Bridge 04 A salt bridge is a U- shaped tube containing a concentrated solution of an inert electrolyte like KCl, KNO3, K2SO4, etc., or solidified solution of such an electrolyte in Agar-Agar and gelatin. These inert electrolytes do not take part in the reduction reaction . The function of the salt bridge is to allow the movement of ions from one solution to the other without mixing two solutions. Thus, whereas electron flow in the outer circuit in the wire, and the inner circuit is completed by the flow of ions from one cell to the other through the salt bridge. The salt bridge maintains the electrical neutrality of the solution in the two half-cells. 05 Mechanism Of Galvanic Cell The chemical reaction responsible for the generation of electric current from chemical energy in a galvanic cell is a redox reaction. This redox reaction is called the cell reaction of the given galvanic cell. A galvanic cell is composed of two half cells, i.e., oxidation half cell and reduction half cell. The oxidation occurs at the oxidation electrode, i.e., at the anode, and involves the liberation of electrons. The reduction occurs at the reduction electrode, i.e., at the cathode, and involves the gain of electrons. The cell reaction is obtained by adding oxidation and reduction halfreactions of Daniel cell. At the anode, oxidation half cell reaction: Zn→Zn2 + + 2eAt the cathode, reduction half cell reaction: Cu2 + + 2e-→Cu The cell reaction (redox reaction): Zn + Cu2 + →Cu + Zn2 + Representation Of Galvanic Cell 06 1. An oxidation and reduction half-cells are represented by putting a single vertical line between the symbols of metal acting as an electrode and the symbol of ion present in the electrolyte in contact with metal. The vertical line represents the phase boundary. 2. In the oxidation half cell, the reduced half is written on the left, whereas in the reduction half cell, the reduced state is written on the right. 3. The molar concentration of the solution is written in the parenthesis after the formula of the ion. M|Mn+(aq) (Oxidation half) Mn+(aq)∣M (Reduction half) 4.The salt bridge that connects to the solution is represented by two parallel vertical lines, i.e., ǁ. Example: Cell representation of Daniel cell Redox reaction occurring in the Daniel cell is : Zn+CuSO4→Cu+ZnSO4 Cell representation: Zn∣∣Zn2+(c1)∥Cu2+(c2)∣∣Cu Daniell Cell 07 Daniel cell is the best example of a galvanic cell. The anode of the Daniel cell consists of a zinc rod dipped in the solution of zinc sulphate (ZnSO4) of concentration C1. The cathode is made by immersing a copper rod in the solution copper sulphate (CuSO4) of concentration C2. The Zn2 + and Cu2+ ions in the solution are made in electrical communication either by direct contact or through a salt bridge. The zinc electrode acts as an anode at which oxidation takes place and the copper electrode acts as a cathode at which reduction occurs. Since electrons are produced at the zinc electrode, this electrode is rich in electrons and pushes the electron into the external circuit. Conversely, the electron-deficient copper electrode pulls the electron from the external circuit. Thus, electrons flow from zinc electrode to copper electrode. 08 Difference between Galvanic and Electrolytic cell Galvanic Cell Electrolytic Cell 1. It is the device to convert chemical energy into electrical energy. 1. It is the device to convert electrical energy into chemical energy. 2. In a galvanic cell, the reaction taking place is spontaneous. 2. In an electrolytic cell, the reaction taking place is non-spontaneous. 3. Two different electrodes are usually set up in two separate beakers. 3. Both the electrodes, either of the same material or different materials, are suspended in the electrolytic solution in the same beaker. 4. Two different electrolytes are taken in two separate beakers. 4. Only one electrolyte is taken. 5. The electrode on which oxidation takes place is called the anode (negative pole), and the electrode on which reduction takes place is the cathode (positive pole). 5. The electrode which is connected to the negative terminal of the battery is called the cathode, and reduction occurs here. Oxidation occurs in the anode, i.e., the electrode connected to the positive terminal. 6. To set this cell, a salt bridge/porous pot is used. 6. No salt bridge is used in the electrolytic cell. 7. Free energy change during the reaction is negative. 7. Free energy change during the reaction is positive. 09 Bibliography Chemistry Part-1 , Textbook for class XII https://www.embibe.com/exams/g alvanic-cell/ https://www.wikipedia.org/ https://glossary.periodni.com/gloss ary.php?en=galvanic https://thesolutionrider.blogspot.co m/ Thankyou!