First Law of Thermodynamics adaptation of the Law of Conservation of Energy differentiates between three types of energy transfer: Heat, Thermodynamic Work, and Energy associated with matter transfer. It also relates each type of energy transfer to a property of a body’s Internal Energy.
The First Law of Thermodynamics states that energy cannot be created or destroyed however, it can be transferred from one form to another. Also, according to the first law of thermodynamics, Heat is a form of energy and the thermodynamic processes (like Isothermal, Isochoric, Adiabatic, Isothermal, and Quasi-Static Processes.) obey the Law of Conservation of Energy.
Table of Contents
What is the First Law of Thermodynamics?
First Law of Thermodynamics states that the total energy of an isolated system is constant. Energy can be transformed from one form to another, but can neither be created nor destroyed.
Internal energy is a state variable in a thermodynamic system that is in equilibrium. The internal energy difference between the two systems is equal to heat transfer into the system minus work done by the system.
According to the First Law of Thermodynamics, the universe’s energy does not change. It can be transferred between the system and the surroundings, but it cannot be produced or destroyed. The law is primarily concerned with energy states as a result of work and heat transmission.
We may use the popular example of a heat engine to help you grasp the meaning of the First Law. Thermal energy is transformed into mechanical energy in a Heat engine, and the process is also reversed. The majority of heat engines are classified as open systems. A heat engine’s primary working concept is to take advantage of the many interactions between heat, pressure, and volume of a working fluid, which is generally a gas. It’s not uncommon for gas to turn into a liquid and then back into a gas.
First Law of Thermodynamics Formula
According to this law, some heat supplied to the system is used to change the internal energy, while the remaining is used by the system to perform work. The mathematical expression of the first law of thermodynamics is given by:
ΔQ = ΔU + ΔW
Where
ΔU is the change in internal energy of the system,
ΔW is the work done by the system, &
ΔQ is the heat supplied to the system.
Limitations of First Law of Thermodynamics
The first law of thermodynamics has a limitation in that it states nothing about the direction of heat flow.
It is not feasible to reverse the procedure. In actuality, the heat does not entirely convert to labor. We could move ships across the ocean by extracting heat from the ocean’s water if it had been feasible to turn all of the heat into work.
It makes no distinction between whether the process is spontaneous or not.
Perpetual Motion Machine of First Kind (PMM1)
It is impossible to build a machine that can do mechanical work indefinitely without spending any energy. The perpetual motion machine of the first type is a hypothetical device like this. These machines contradict the first rule of thermodynamics and do not exist in the actual world.
First Law of Thermodynamics for a Closed System
The product of the pressure applied and the change in volume that happens as a result of the applied pressure is the work done for a closed system:
W = – P ΔV
Where
P denotes the system’s constant external pressure, and
V denotes the volume change.
This is referred to as Pressure-Volume work.
The internal energy of a system rises or falls in response to work interactions that occur across its limits. When work is done on the system, the internal energy increases, but it decreases when work is done by the system. Any heat exchange between the system and its surroundings alters the system’s internal energy. However, the total change in internal energy is always zero since energy remains constant (according to the first rule of thermodynamics). If the system loses energy, it is absorbed by the surroundings. If energy is absorbed into a system, the energy must have been released by the environment:
ΔUsystem = −ΔUsurroundings
Where
ΔUsystem is the change in the total internal energy of the system, and
ΔUsurroundings is the change in the total energy of the surrounding.
Solved Examples on First Law of Thermodynamics
Example 1: Find out the internal energy of a system that has constant volume and the heat around the system is increased by 30 J.
Solution:
Given that,
Heat Transfer, ΔQ = 30 J
For constant volume, ΔV = 0
W = P ΔV = 0
The formula for internal energy is given as:
ΔU = ΔQ – W
⇒ ΔU = 30 J – 0
⇒ ΔU = 30 J
Hence, the change in internal energy of the system is 30 J.
Example 2: Calculate the change in the internal energy of the system if 2000 J of heat is added to a system and a work of 1500 J is done.
Solution:
Given that,
Heat added to a system, ΔQ = 2000 J
Work done on the system, W = 1500 J
The formula for internal energy is given as:
ΔU = ΔQ – W
⇒ ΔU = 2000 J – 1500 J
⇒ ΔU = 500 J
Hence, the change in internal energy of the system is 500 J.
Example 3: A gas in a closed container is heated with 20 J of energy, causing the lid of the container to rise 3 m with 4 N of force. What is the total change in energy of the system?
Solution:
Given that,
Heat supplied to the container, ΔQ = 20 J
Rise in lid of the container, Δx = 3 m
Force applied on the container, F = 4 N
We are not given a value for work, but we can solve for it using the force and distance. Work is the product of force and displacement.
W = F Δx
⇒ W = 4 N × 3 m
⇒ W = 12 J
The formula for internal energy is given as:
ΔU = ΔQ – W
⇒ ΔU = 20 J – 12 J
⇒ ΔU = 8 J
Hence, the change in internal energy of the system is 8 J.
Example 4: Determine the change in the internal energy of the system when gas in a cylinder is fitted with a frictionless piston expands against a constant external pressure of 1 atm from a volume of 2 liters to a volume of 5 liters. So it absorbs 100 J of thermal energy from its surroundings.
Answer:
Given that,
Q = 100 J
V1 = 2 L
V2 = 5 L
Then, according to the formula:
ΔU = Q – PΔV
⇒ ΔU = Q – P(V2 – V1)
Therefore,
ΔU = Q – P(V2 – V1)
⇒ ΔU = 100 J – 1 (5 – 2) 101.33 J
⇒ ΔU = -203.99 J
FAQs on First Law of Thermodynamics
What is the First Law of Thermodynamics?
The first law of thermodynamics deals with work done and heat energy supplied or removed from a system. The First Law of Thermodynamics states that the total energy of an isolated system is constant. Energy can be transformed from one form to another, but can neither be created nor destroyed.
State the Mathematical Form of the First Law of Thermodynamics.
The mathematical expression of the first law of thermodynamics is given by,
ΔQ = ΔU + ΔW
where
ΔU is the change in internal energy of the system,
ΔW is the work done by the system, &
ΔQ is the heat supplied to the system.
What is the Significance of the First Law of Thermodynamics to the Environment?
Energy cannot be generated or destroyed, according to the first law; it can only be changed from one form to another. All living species on Earth rely on the sun for their energy.
Photosynthesis is the process through which plants transform solar energy into chemical energy. These energies are not returned to the solar system by the plants; instead, they are passed on to herbivores that eat green vegetation.
Carnivores use some energy gained by herbivores, while some energy obtained by herbivores is passed to decomposers when the herbivores die.
Name the Law of Conservation which is followed by the First Law of Thermodynamics.
The Law of Conservation of Energy is followed by the First Law of Thermodynamics.
What is an Isolated System?
An Isolated System is an open system in which the exchange of both energy and matter with its surroundings takes place.
What are the Applications of the First Law of Thermodynamics?
The First Law of Thermodynamics exhibit a wide variety of applications in the field of Physics. Here are the Applications of the First Law of Thermodynamics: In Engines, Refrigerator, Thermal Power Plants, etc.
Name those physical parameters of matter for which the First Law of Thermodynamics provides the relation.
The First law of thermodynamics furnishes the relationship between heat, work, and the internal energy of the system i.e. the properties of the system.
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.
CBSE Class 11 Chemistry Syllabus is a vast which needs a clear understanding of the concepts and topics. Knowing CBSE Class 11 Chemistry syllabus helps students to understand the course structure of Chemistry.
Unit-wise CBSE Class 11 Syllabus for Chemistry
Below is a list of detailed information on each unit for Class 11 Students.
UNIT I – Some Basic Concepts of Chemistry
General Introduction: Importance and scope of Chemistry.
Nature of matter, laws of chemical combination, Dalton’s atomic theory: concept of elements, atoms and molecules.
Atomic and molecular masses, mole concept and molar mass, percentage composition, empirical and molecular formula, chemical reactions, stoichiometry and calculations based on stoichiometry.
UNIT II – Structure of Atom
Discovery of Electron, Proton and Neutron, atomic number, isotopes and isobars. Thomson’s model and its limitations. Rutherford’s model and its limitations, Bohr’s model and its limitations, concept of shells and subshells, dual nature of matter and light, de Broglie’s relationship, Heisenberg uncertainty principle, concept of orbitals, quantum numbers, shapes of s, p and d orbitals, rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of atoms, stability of half-filled and completely filled orbitals.
UNIT III – Classification of Elements and Periodicity in Properties
Significance of classification, brief history of the development of periodic table, modern periodic law and the present form of periodic table, periodic trends in properties of elements -atomic radii, ionic radii, inert gas radii, Ionization enthalpy, electron gain enthalpy, electronegativity, valency. Nomenclature of elements with atomic number greater than 100.
UNIT IV – Chemical Bonding and Molecular Structure
Valence electrons, ionic bond, covalent bond, bond parameters, Lewis structure, polar character of covalent bond, covalent character of ionic bond, valence bond theory, resonance, geometry of covalent molecules, VSEPR theory, concept of hybridization, involving s, p and d orbitals and shapes of some simple molecules, molecular orbital theory of homonuclear diatomic molecules(qualitative idea only), Hydrogen bond.
UNIT V – Chemical Thermodynamics
Concepts of System and types of systems, surroundings, work, heat, energy, extensive and intensive properties, state functions. First law of thermodynamics – internal energy and enthalpy, measurement of U and H, Hess’s law of constant heat summation, enthalpy of bond dissociation, combustion, formation, atomization, sublimation, phase transition, ionization, solution and dilution. Second law of Thermodynamics (brief introduction) Introduction of entropy as a state function, Gibb’s energy change for spontaneous and nonspontaneous processes. Third law of thermodynamics (brief introduction).
UNIT VI – Equilibrium
Equilibrium in physical and chemical processes, dynamic nature of equilibrium, law of mass action, equilibrium constant, factors affecting equilibrium – Le Chatelier’s principle, ionic equilibrium- ionization of acids and bases, strong and weak electrolytes, degree of ionization, ionization of poly basic acids, acid strength, concept of pH, hydrolysis of salts (elementary idea), buffer solution, Henderson Equation, solubility product, common ion effect (with illustrative examples).
UNIT VII – Redox Reactions
Concept of oxidation and reduction, redox reactions, oxidation number, balancing redox reactions, in terms of loss and gain of electrons and change in oxidation number, applications of redox reactions.
UNIT VIII – Organic Chemistry: Some basic Principles and Techniques
General introduction, classification and IUPAC nomenclature of organic compounds. Electronic displacements in a covalent bond: inductive effect, electromeric effect, resonance and hyper conjugation. Homolytic and heterolytic fission of a covalent bond: free radicals, carbocations, carbanions, electrophiles and nucleophiles, types of organic reactions.
UNIT IX – Hydrocarbons
Classification of Hydrocarbons Aliphatic Hydrocarbons: Alkanes – Nomenclature, isomerism, conformation (ethane only), physical properties, chemical reactions. Alkenes – Nomenclature, structure of double bond (ethene), geometrical isomerism, physical properties, methods of preparation, chemical reactions: addition of hydrogen, halogen, water, hydrogen halides (Markovnikov’s addition and peroxide effect), ozonolysis, oxidation, mechanism of electrophilic addition. Alkynes – Nomenclature, structure of triple bond (ethyne), physical properties, methods of preparation, chemical reactions: acidic character of alkynes, addition reaction of – hydrogen, halogens, hydrogen halides and water.
Aromatic Hydrocarbons:
Introduction, IUPAC nomenclature, benzene: resonance, aromaticity, chemical properties: mechanism of electrophilic substitution. Nitration, sulphonation, halogenation, Friedel Craft’s alkylation and acylation, directive influence of functional group in monosubstituted benzene. Carcinogenicity and toxicity.
To know the CBSE Syllabus for all the classes from 1 to 12, visit the Syllabus page of CBSE. Meanwhile, to get the Practical Syllabus of Class 11 Chemistry, read on to find out more about the syllabus and related information in this page.
CBSE Class 11 Chemistry Practical Syllabus with Marking Scheme
In Chemistry subject, practical also plays a vital role in improving their academic scores in the subject. The overall weightage of Chemistry practical mentioned in the CBSE Class 11 Chemistry syllabus is 30 marks. So, students must try their best to score well in practicals along with theory. It will help in increasing their overall academic score.
CBSE Class 11 Chemistry Practical Syllabus
The experiments will be conducted under the supervision of subject teacher. CBSE Chemistry Practicals is for 30 marks. This contribute to the overall practical marks for the subject.
The table below consists of evaluation scheme of practical exams.
Evaluation Scheme
Marks
Volumetric Analysis
08
Salt Analysis
08
Content Based Experiment
06
Project Work
04
Class record and viva
04
Total
30
CBSE Syllabus for Class 11 Chemistry Practical
Micro-chemical methods are available for several of the practical experiments. Wherever possible such techniques should be used.
A. Basic Laboratory Techniques 1. Cutting glass tube and glass rod 2. Bending a glass tube 3. Drawing out a glass jet 4. Boring a cork
B. Characterization and Purification of Chemical Substances 1. Determination of melting point of an organic compound. 2. Determination of boiling point of an organic compound. 3. Crystallization of impure sample of any one of the following: Alum, Copper Sulphate, Benzoic Acid.
C. Experiments based on pH
1. Any one of the following experiments:
Determination of pH of some solutions obtained from fruit juices, solution of known and varied concentrations of acids, bases and salts using pH paper or universal indicator.
Comparing the pH of solutions of strong and weak acids of same concentration.
Study the pH change in the titration of a strong base using universal indicator.
2. Study the pH change by common-ion in case of weak acids and weak bases.
D. Chemical Equilibrium One of the following experiments:
1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing the concentration of either of the ions. 2. Study the shift in equilibrium between [Co(H2O)6] 2+ and chloride ions by changing the concentration of either of the ions.
E. Quantitative Estimation i. Using a mechanical balance/electronic balance. ii. Preparation of standard solution of Oxalic acid. iii. Determination of strength of a given solution of Sodium hydroxide by titrating it against standard solution of Oxalic acid. iv. Preparation of standard solution of Sodium carbonate. v. Determination of strength of a given solution of hydrochloric acid by titrating it against standard Sodium Carbonatesolution.
F. Qualitative Analysis 1) Determination of one anion and one cation in a given salt Cations‐ Pb2+, Cu2+, As3+, Al3+, Fe3+, Mn2+, Ni2+, Zn2+, Co2+, Ca2+, Sr2+, Ba2+, Mg2+, NH4+ Anions – (CO3)2‐ , S2‐, NO2‐ , SO32‐, SO2‐ , NO ‐ , Cl‐ , Br‐, I‐, PO43‐ , C2O2‐ ,CH3COO‐ (Note: Insoluble salts excluded)
2) Detection of ‐ Nitrogen, Sulphur, Chlorine in organic compounds.
G) PROJECTS Scientific investigations involving laboratory testing and collecting information from other sources.
A few suggested projects are as follows:
Checking the bacterial contamination in drinking water by testing sulphide ion
Study of the methods of purification of water.
Testing the hardness, presence of Iron, Fluoride, Chloride, etc., depending upon the regional variation in drinking water and study of causes of presence of these ions above permissible limit (if any).
Investigation of the foaming capacity of different washing soaps and the effect of addition of Sodium carbonate on it.
Study the acidity of different samples of tea leaves.
Determination of the rate of evaporation of different liquids Study the effect of acids and bases on the tensile strength of fibres.
Study of acidity of fruit and vegetable juices.
Note: Any other investigatory project, which involves about 10 periods of work, can be chosen with theapproval of the teacher.
Practical Examination for Visually Impaired Students of Class 11
Below is a list of practicals for the visually impaired students.
A. List of apparatus for identification for assessment in practicals (All experiments) Beaker, tripod stand, wire gauze, glass rod, funnel, filter paper, Bunsen burner, test tube, test tube stand, dropper, test tube holder, ignition tube, china dish, tongs, standard flask, pipette, burette, conical flask, clamp stand, dropper, wash bottle • Odour detection in qualitative analysis • Procedure/Setup of the apparatus
B. List of Experiments A. Characterization and Purification of Chemical Substances 1. Crystallization of an impure sample of any one of the following: copper sulphate, benzoic acid B. Experiments based on pH 1. Determination of pH of some solutions obtained from fruit juices, solutions of known and varied concentrations of acids, bases and salts using pH paper 2. Comparing the pH of solutions of strong and weak acids of same concentration.
C. Chemical Equilibrium 1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing the concentration of eitherions. 2. Study the shift in equilibrium between [Co(H2O)6]2+ and chloride ions by changing the concentration of either of the ions.
D. Quantitative estimation 1. Preparation of standard solution of oxalic acid. 2. Determination of molarity of a given solution of sodium hydroxide by titrating it against standard solution of oxalic acid.
E. Qualitative Analysis 1. Determination of one anion and one cation in a given salt 2. Cations – NH+4 Anions – (CO3)2-, S2-, (SO3)2-, Cl-, CH3COO- (Note: insoluble salts excluded) 3. Detection of Nitrogen in the given organic compound. 4. Detection of Halogen in the given organic compound.
Note: The above practicals may be carried out in an experiential manner rather than recording observations.
We hope students must have found this information on CBSE Syllabus useful for their studying Chemistry. Learn Maths & Science in interactive and fun loving ways with ANAND CLASSES (A School Of Competitions) App/Tablet.
Frequently Asked Questions on CBSE Class 11 Chemistry Syllabus
Q1
How many units are in the CBSE Class 11 Chemistry Syllabus?
There are 9 units in the CBSE Class 11 Chemistry Syllabus. Students can access various study materials for the chapters mentioned in this article for free at ANAND CLASSES (A School Of Competitions).
Q2
What is the total marks for practicals examination as per the CBSE Class 11 Chemistry Syllabus?
The total marks for the practicals as per the CBSE Class 11 Chemistry Syllabus is 30. It includes volumetric analysis, content-based experiment, salt analysis, class record, project work and viva.
Q3
Which chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry?
The organic chemistry chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry.
Anand Technical Publishers
Buy Products (Printed Books & eBooks) of Anand Classes published by Anand Technical Publishers, Visit at following link :
