The various forms of energy are interconnected, and they can be converted from one form to another under certain conditions.
The field of science known as thermodynamics is related to the study of various kinds of energy and its conversion. In thermodynamics, the system refers to the part of the universe that is being observed, whereas the surrounding refers to the rest of the universe that isn’t part of the system.
Every substance has a specific amount of energy that is determined by the substance’s type, such as, temperature, and pressure. Internal energy is the terminology for this.
The internal energy change as a state function or as a state of the system is described further down.
Table of Contents
What is the State of a System?
A system’s state is defined as its state of existence when its macroscopic characteristics have definite values.
The state of the system is said to change if any of the system’s macroscopic characteristics change.
State variables are the measurable properties needed to describe a system’s state. The state variables are temperature, pressure, volume, composition, and so on.
Consider the case of a system formed of an ideal gas. Only three variables, such as temperature, pressure, and volume, may define the state of this system.
A state function is a system property whose value is solely determined by the system’s state and is unaffected by the path or method by which that state is attained. The initial and final states of the system, not the path by which they are obtained, determine the change in the value of these properties.
The system’s thermodynamic state is a crucial term. The system is in some particular state at any given time, which may be described using values of macroscopic properties that are relevant to our objectives.
The current state of the system is defined by the values of these characteristics at any given time. The state changes whenever the value of any of these properties changes.
If it can be later discovered that each of the important properties has the same value as it did at a previous point in time, it can be observed that the system has reverted to its previous state.
The state of the system should not be mixed up with the type of physical state or phase aggregation state. A change of state refers to a shift in the system’s state rather than a phase transition.
Internal Energy
Every substance has a specific amount of energy that is determined by factors like the chemical nature of the substance, temperature, and pressure. The term “intrinsic energy” or “internal energy” refers to this type of energy. The letter U is used to signify it (earlier it was represented by the symbol E). It is made up of the individual particles’ kinetic energy and potential energy.
Translational energy, rational energy, vibrational energy, and other forms of kinetic energy emerge from the motion of its particles. Electronic energy, energy due to molecular interactions, nuclear energy, and other types of interactions between particles all contribute to potential energy.
Although traditional thermodynamics is concerned with the macroscopic characteristics of materials, such as temperature, pressure, and volume, thermal energy is understood at the microscopic level as a rise in the kinetic energy of motion of the molecules that make up a substance. The translational kinetic energy of gas molecules, for example, is proportional to the temperature of the gas, the molecules can rotate around their centre of mass, and the constituent atoms can vibrate with respect to each other.
Chemical energy is also stored in the bonds that hold molecules together, and weaker long-range interactions between molecules require even more energy. The total internal energy of a substance in a particular thermodynamic state is the sum of all these kinds of energy. A system’s total energy contains its internal energy as well as any external sources of energy, such as kinetic energy from the system’s overall motion, and gravitational potential energy from its elevation.
Internal energy is the sum of all forms of energy stored in atoms or molecules.
Depending on the nature of the constituent atoms, bonds, and various temperatures, pressure, and other conditions, different substances have varying internal energies. Even under equal temperature and pressure conditions, the internal energy of 1 mole of carbon dioxide will differ from the internal energy of 1 mole of sulphur dioxide. Furthermore, under the same atmospheric pressure, the internal energy of one mole of water at 300K differs from that of one mole of water at 310K.
Internal Energy as the State of System
A variety of thermodynamic characteristics, such as pressure, volume, temperature, internal energy, and enthalpy, can be used to define a thermodynamic system. These are grouped into two categories: state functions and path functions. A state function is a property of a system whose value is determined by the system’s initial and final states. These types of functions explain a function’s equilibrium state and are unaffected by how the system got there. Internal energy, for example, is a state function that is independent of the path taken to change the system’s state.
It is a system’s overall energy. This consists of a number of components, including molecule translational kinetic energy, bond energy, electronic energy, and the intermolecular interaction energy of the system’s constituents’ particles, among others. Internal energy is affected by factors such as pressure, volume, and temperature. All of the variables in this list are state functions. Mass, volume, pressure, temperature, density, and entropy are all examples of state functions. Some factors are influenced by the amount of matter present. Intensive properties are factors that are independent of the amount of matter present.
Density is an example. A state function is a property of a system that is dependent only on the system’s state and not on the process by which it is achieved. Internal energy is independent of the path used to get from one condition to the next. It depends on the system’s current state.
Since accurate values of different types of energies are stored in a system, such as translational, vibrational, rational, chemical, and so on, it is impossible to compute the absolute value of internal energy possessed by a substance. The difference between the internal energies of the two states can be used to calculate the change in the internal energy of a reaction.
Let’s denote the internal energies in states A and B as UA and UB, respectively. The difference in internal energy between the two states will be,
∆U=UB – UA
The internal energy difference (∆U) has a set value and is unaffected by the path followed between two states A and B. The difference between the products’ and reactants’ internal energies, i.e. the change in internal energy, can be considered for chemical reactions.
∆U=Uproducts – Ureactants
∆U =Up – Ur
where Up denotes the internal energy of the products, Ur denotes the internal energy of the reactants, and ∆U denotes the internal energy change.
∆U is positive if the internal energy of the products is greater than the internal energy of the reactants.
This means that if Up > Ur, then ∆U =Up – Ur = positive.
If the internal energy of the products is smaller than the internal energy of the reactants, then ∆U will be negative.
This means that if Up < Ur, then ∆U =Up – Ur = negative.
As a result, the internal energy, U, is a state system, that is, the internal energy is a property of the system whose value is solely determined by the system’s state. This means that the difference in internal energy U is independent of the path and only depends on the initial and final states.
Sample Questions
Question 1: What significance does internal energy have?
Answer:
Since the possible energies between molecules and atoms are crucial, the internal energy is important for understanding phase shifts, chemical reactions, nuclear events, and many other microscopic phenomena. In a vacuum, both objects have macroscopic and microscopic energy.
Question 2: What affects internal energy?
Answer:
Internal energy can be changed by altering the temperature or volume of an object without changing the number of particles inside. As the temperature of a system rises, the molecules move faster, resulting in higher kinetic energy and hence an increase in internal energy.
Question 3: Is internal energy a state function?
Answer:
A state function describes the equilibrium state of a system, as well as the system itself. Since the internal energy U is defined by the quantities that determine the state of the system at equilibrium, it is called a state function because any change in energy is entirely determined by the system’s initial and final states.
Question 4: Is the internal energy affected by the system’s path?
Answer:
The internal energy U is totally defined by the quantities that determine the equilibrium state of the system, therefore any change in energy is entirely governed by the system’s initial and final states. As a result, the internal energy is independent of the system’s path.
Question 5: When will the internal energy difference be negative?
Answer:
When the internal energy of the products is smaller than the internal energy of the reactants, i.e. Up < Ur then the internal energy difference ∆U will be negative.
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.
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