An electrolytic cell can be defined as an electrochemical device that uses electrical energy to facilitate a non-spontaneous redox reaction. Electrolytic cells are electrochemical cells that can be used for the electrolysis of certain compounds. For example, water can be subjected to electrolysis (with the help of an electrolytic cell) to form gaseous oxygen and gaseous hydrogen. This is done by using the flow of electrons (into the reaction environment) to overcome the activation energy barrier of the non-spontaneous redox reaction.
Table of Contents
The three primary components of electrolytic cells are:
Cathode (which is negatively charged for electrolytic cells)
Anode (which is positively charged for electrolytic cells)
Electrolyte
The electrolyte provides the medium for the exchange of electrons between the cathode and the anode. Commonly used electrolytes in electrolytic cells include water (containing dissolved ions) and molten sodium chloride.
Comparison Between Galvanic Cells and Electrolytic Cells
Galvanic Cell (or Voltaic Cell)
Electrolytic Cell
Converts chemical energy into electrical energy.
Converts electrical energy into chemical energy.
Contain negatively charged anodes and positively charged cathodes.
Contain positively charged anode and negatively charged cathode.
Feature spontaneous cell reactions.
Feature non-spontaneous cell reactions.
Diagram and Working of an Electrolytic Cell
Molten sodium chloride (NaCl) can be subjected to electrolysis with the help of an electrolytic cell, as illustrated below.
Here, two inert electrodes are dipped into molten sodium chloride (which contains dissociated Na+ cations and Cl– anions). When an electric current is passed into the circuit, the cathode becomes rich in electrons and develops a negative charge. The positively charged sodium cations are now attracted towards the negatively charged cathode. This results in the formation of metallic sodium at the cathode.
Simultaneously, the chlorine atoms are attracted to the positively charged cathode. This results in the formation of chlorine gas (Cl2) at the anode (which is accompanied by the liberation of 2 electrons, finishing the circuit). The associated chemical equations and the overall cell reaction are provided below.
Reaction at Cathode: [Na+ + e– → Na] x 2
Reaction at Anode: 2Cl– → Cl2 + 2e–
Cell Reaction: 2NaCl → 2Na + Cl2
Thus, molten sodium chloride can be subjected to electrolysis in an electrolytic cell to generate metallic sodium and chlorine gas as the products.
Applications of Electrolytic Cells
The primary application of electrolytic cells is for the production of oxygen gas and hydrogen gas from water.
They are also used for the extraction of aluminium from bauxite.
Another notable application of electrolytic cells is in electroplating, which is the process of forming a thin protective layer of a specific metal on the surface of another metal.
The electrorefining of many non-ferrous metals is done with the help of electrolytic cells.
Such electrochemical cells are also used in electrowinning processes.
It can be noted that the industrial production of high-purity copper, high-purity zinc, and high-purity aluminium is almost always done through electrolytic cells.
To learn more about electrolytic cells and other important concepts in electrochemistry, register with ANAND CLASSES (A School Of Competitions) and download the mobile application on your smartphone.
Frequently Asked Questions – FAQs
Q1
What are the key differences between electrolytic cells and Galvanic cells?
The cell reactions of electrolytic cells are non-spontaneous whereas the cell reactions of Galvanic cells are spontaneous. Galvanic cells generate electrical energy from chemical reactions whereas electrolytic cells generate non-spontaneous redox reactions from an input of electrical energy.
Q2
What are the three primary components of electrolytic cells?
The three main components of electrolytic cells include the cathode, the anode, and the electrolyte. In electrolytic cells (as is the case in most electrochemical cells), oxidation occurs at the anode and reduction occurs at the cathode.
Q3
What kinds of charges are held by the electrodes of electrolytic cells?
In electrolytic cells, the cathode is negatively charged and the anode is positively charged. The positively charged ions flow towards the cathode whereas the negatively charged ions flow towards the anode.
Q4
What are the uses of electrolytic cells?
Electrolytic cells can be used to produce oxygen gas and hydrogen gas from water by subjecting it to electrolysis. These devices can also be used to obtain chlorine gas and metallic sodium from aqueous solutions of sodium chloride (common salt). Another important application of electrolytic cells is in electroplating.
Q5
How do electrolytic cells work?
When an external electric current flows into the cathode of the electrolytic cell, the resulting negative charge attracts the dissociated positive ions present in the electrolyte. This results in the deposition of the positively charged ions onto the cathode. At the same time, the negatively charged ions flow towards the anode, which is positively charged.
Neeraj Anand, Param Anand
Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations.
In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS".
He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.
Below is the CBSE Class 12 Syllabus along with the marking scheme and time duration of the Chemistry exam.
S.No
Title
No. of Periods
Marks
1
Solutions
10
7
2
Electrochemistry
12
9
3
Chemical Kinetics
10
7
4
d -and f -Block Elements
12
7
5
Coordination Compounds
12
7
6
Haloalkanes and Haloarenes
10
6
7
Alcohols, Phenols and Ethers
10
6
8
Aldehydes, Ketones and Carboxylic Acids
10
8
9
Amines
10
6
10
Biomolecules
12
7
Total
70
CBSE Class 12 Chemistry Practical Syllabus along with Marking Scheme
The following is a breakdown of the marks for practical, project work, class records, and viva. The total number of marks for all parts is 15. The marks for both terms are provided in the table below.
Evaluation Scheme for Examination
Marks
Volumetric Analysis
08
Salt Analysis
08
Content-Based Experiment
06
Project Work and Viva
04
Class record and Viva
04
Total
30
CBSE Class 12 Chemistry Syllabus (Chapter-wise)
Unit -1: Solutions
Raoult's law.
Colligative properties - relative lowering of vapour pressure, elevation of boiling point, depression of freezing point, osmotic pressure, determination of molecular masses using colligative properties, abnormal molecular mass.
Solutions, Types of solutions, expression of concentration of solutions of solids in liquids, solubility of gases in liquids, solid solutions.
Van't Hoff factor.
Unit -2: Electrochemistry
Redox reactions, EMF of a cell, standard electrode potential
Nernst equation and its application to chemical cells
Relation between Gibbs energy change and EMF of a cell
Kohlrausch's Law
Electrolysis and law of electrolysis (elementary idea)
Dry cell-electrolytic cells and Galvanic cells
Conductance in electrolytic solutions, specific and molar conductivity, variations of conductivity with concentration.
Lead accumulator
Fuel cells
Unit -3: Chemical Kinetics
Rate of a reaction (Average and instantaneous)
Rate law and specific rate constant
Integrated rate equations and half-life (only for zerfirst-order order reactions)
Concept of collision theory (elementary idea, no mathematical treatment)
Factors affecting rate of reaction: concentration, temperature, catalyst;
Order and molecularity of a reaction
Activation energy
Arrhenius equation
Unit -4: d and f Block Elements
Lanthanoids- Electronic configuration, oxidation states, chemical reactivity and lanthanoid contraction and its consequences.
Actinoids- Electronic configuration, oxidation states and comparison with lanthanoids.
General introduction, electronic configuration, occurrence and characteristics of transition metals, general trends in properties of the first-row transition metals – metallic character, ionization enthalpy, oxidation states, ionic radii, color, catalytic property, magnetic properties, interstitial compounds, alloy formation, preparation and properties of K2Cr2O7 and KMnO4.
Unit -5: Coordination Compounds
Coordination compounds - Introduction, ligands, coordination number, color, magnetic properties and shapes
The importance of coordination compounds (in qualitative analysis, extraction of metals and biological system).
IUPAC nomenclature of mononuclear coordination compounds.
Bonding
Werner's theory, VBT, and CFT; structure and stereoisomerism
Unit -6: Haloalkanes and Haloarenes
Haloarenes: Nature of C–X bond, substitution reactions (Directive influence of halogen in monosubstituted compounds only). Uses and environmental effects of - dichloromethane, trichloro methane, tetrachloromethane, iodoform, freons, DDT.
Haloalkanes: Nomenclature, nature of C–X bond, physical and chemical properties, optical rotation mechanism of substitution reactions.
Unit -7: Alcohols, Phenols and Ethers
Phenols: Nomenclature, methods of preparation, physical and chemical properties, acidic nature of phenol, electrophilic substitution reactions, uses of phenols.
Ethers: Nomenclature, methods of preparation, physical and chemical properties, uses.
Alcohols: Nomenclature, methods of preparation, physical and chemical properties (of primary alcohols only), identification of primary, secondary and tertiary alcohols, mechanism of dehydration, and uses with special reference to methanol and ethanol.
Unit -8: Aldehydes, Ketones and Carboxylic Acids
Carboxylic Acids: Nomenclature, acidic nature, methods of preparation, physical and chemical properties; uses.
Aldehydes and Ketones: Nomenclature, nature of carbonyl group, methods of preparation, physical and chemical properties, mechanism of nucleophilic addition, the reactivity of alpha hydrogen in aldehydes, uses.
Unit -9: Amines
Diazonium salts: Preparation, chemical reactions and importance in synthetic organic chemistry.
Amines: Nomenclature, classification, structure, methods of preparation, physical and chemical properties, uses, and identification of primary, secondary and tertiary amines.
Unit -10: Biomolecules
Proteins -Elementary idea of - amino acids, peptide bond, polypeptides, proteins, structure of proteins - primary, secondary, tertiary structure and quaternary structures (qualitative idea only), denaturation of proteins; enzymes. Hormones - Elementary idea excluding structure.
Vitamins - Classification and functions.
Carbohydrates - Classification (aldoses and ketoses), monosaccharides (glucose and fructose), D-L configuration oligosaccharides (sucrose, lactose, maltose), polysaccharides (starch, cellulose, glycogen); Importance of carbohydrates.
Nucleic Acids: DNA and RNA.
The syllabus is divided into three parts: Part A, Part B, and Part C. Part A consist of Basic Concepts of Chemistry, which covers topics such as atomic structure, chemical bonding, states of matter, and thermochemistry. Part B consists of Topics in Physical Chemistry, which includes topics such as chemical kinetics, equilibrium, and electrochemistry. Part C consists of Topics in Organic Chemistry, which covers topics such as alkanes, alkenes, alkynes, and aromatic compounds.
Basic Concepts of Chemistry:
Atomic structure: This section covers the fundamental concepts of atomic structure, including the electronic configuration of atoms, the Bohr model of the atom, and the wave nature of matter.
Chemical bonding: This section covers the different types of chemical bonds, including ionic, covalent, and metallic bonds, as well as the concept of hybridization.
States of the matter: This section covers the three states of matter - solid, liquid, and gas - and the factors that influence their properties.
Thermochemistry: This section covers the principles of thermochemistry, including the laws of thermodynamics and the concept of enthalpy.
Chapters in Physical Chemistry:
Chemical kinetics: This section covers the study of the rate of chemical reactions and the factors that influence it, including the concentration of reactants, temperature, and the presence of catalysts.
Equilibrium: This section covers the principles of chemical equilibrium, including the concept of Le Chatelier's principle and the equilibrium constant.
Electrochemistry: This section covers the principles of electrochemistry, including the concept of half-cell reactions, galvanic cells, and electrolysis.
Chapters in Organic Chemistry:
Alkanes: This section covers the properties and reactions of alkanes, including their structure, isomerism, and combustion.
Alkenes: This section covers the properties and reactions of alkenes, including their structure, isomerism, and addition reactions.
Alkynes: This section covers the properties and reactions of alkynes, including their structure, isomerism, and addition reactions.
Aromatic compounds: This section covers the properties and reactions of aromatic compounds, including their structure, isomerism, and electrophilic substitution reactions.
In addition to the topics covered in the syllabus, the CBSE Class 12 Chemistry exam also tests students on their analytical and problem-solving skills, as well as their ability to apply the concepts learned in the classroom to real-world situations.
Students can also check out the Tips for the Class 12 Chemistry Exam. They can easily access the Class 12 study material in one place by visiting the CBSE Class 12 page at ANAND CLASSES (A School Of Competitions). Moreover, to get interactive lessons and study videos, download the ANAND CLASSES (A School Of Competitions) App.
Frequently Asked Questions on CBSE Class 12 Chemistry Syllabus
Q1
How many chapters are there in the CBSE Class 12 Chemistry as per the syllabus?
There are 10 chapters in the CBSE Class 12 Chemistry as per Syllabus. Students can learn all these chapters efficiently using the study materials provided at ANAND CLASSES (A School Of Competitions).
Q2
What is the marking scheme for CBSE Class 12 Chemistry practical exam according to the syllabus?
The marking scheme for CBSE Class 12 Chemistry practical exam, according to the syllabus, is 8 marks for volumetric analysis, 8 marks for salt analysis, 6 marks for the content-based experiment, 4 marks for the project and viva and 4 marks for class record and viva.
Q3
Which is the scoring chapter in Chemistry as per CBSE Class 12 syllabus?
The chapter Electrochemistry in Chemistry is the scoring chapter as per CBSE Class 12 syllabus.
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