TEST -  ATOMIC STRUCTURE

     This is the first test which i have published on this blog. I hope
     that this test will be useful to all my readers and i welcome 
     suggestions on how to make tests better in the future.

    Answers to this test will be posted on Friday night. I have tried
    to ensure that there are no errors. However, if you find any errors
    feel free to post a comment about the error with the question no.

                                      ALL THE BEST

   

                                      ENERGETICS

      Energetics is an important topic for both jee main and advanced
      It is a high scoring chapter and a good hold on concepts and
      formulae will be enough to score well. Energetics consists of
      both thermodynamics and thermochemistry. Thermodynamics
      forms an integral part of physics for jee advanced while
      thermochemistry is exclusive to chemistry.

      Important Points:

      1. When energy is transferred as heat, the transfer stimulates
           random motion. When a system does work, it stimulates
           orderly motion.
     
      2.  In chemistry, work done by the system on the surroundings
           is given a negative sign.

      3.  Internal energy does not include the kinetic energy arising 
           from the motion of a system.

      4.  Internal energy is a state function.
  
      5.  In an ideal gas, the internal energy is independent of the
           volume occupied by the gas.

      6.  Internal energy increases with increase in temperature.

      7.  Both work and heat are path functions.


      

      
      Intensive and Extensive properties:

      Intensive -  Temperature , Density, Resistance, Pressure ,
                         standard electrode potential , molar volume 

      Extensive - mass, volume, internal energy , heat capacity ,
                         enthalpy , entropy, Gibbs energy , mole


      Enthalpy:

      1. It is the energy supplied as heat at constant pressure.
   
      2. H = U + PV

      3. For an ideal gas only ,  H = U + nRT

      4. Enthalpy is a state function


      Important formulae :

        
               

         
      

       Thermochemistry:

       
       Important Points:

       

    

       
       Note:
     
       Heat of formation of nitrous oxide ,  nitrogen dioxide , nitric
       oxide are positive.

      Most stable form of phosphorous at 1 atm is black phosphorous.

      Calorific value -  It is the value of heat produced by burning 
                                  1 gram of fuel.
  
      

     I have attached 2 questions from P. Bahadur which will
     strengthen your hold on thermochemistry. 

   

      

      

    
       
     
    Third Law of Thermodynamics:

    1. At 0 K, the entropy of a pure crystal is 0.

    2. However there are exceptions to this. eg. Ice , CO2 etc.
        These compounds have some residual entropy.


     I am certain that all of you will be comfortable in calculating
     work done in the common processes. Hence , i have not covered
     this. Remember that the direct formula in the case of adiabatic
     process is applicable only in the reversible case. Polytropic
     processes will be covered in physics and are generally not 
     asked in chemistry.

    Thank you all for reading the notes for this chapter.

                               Always remember

                           CHEMISTRY IS EASY


  



   

    ATOMIC STRUCTURE

          Atomic structure is an important chapter in jee advanced in 

       both physics and chemistry. Many questions from this chapter 

       are straightforward and a good hold on concepts will help one

       to score well in modern physics too.

       

        

     Postulates of Bohr's theory

     1. The electron in the hydrogen atom can move around the 

         nucleus in a circular path of fixed radius and energy. These

         paths are called orbits.

   

     2. The energy of an electron in an orbit does not change with 

         time. However electrons can move between different orbits.

     3. Angular momentum is quantised.

  

     Quantum numbers:

     1. Only n,l,m were derived from Schrodinger's equation.

    
     2. Energy is decide by both n,l.

     
     3. An electron in an orbital with quantum number 'm' has a z

    component of angular momentum = m* reduced Planck constant

    
     4. When lines of hydrogen spectrum were observed using high 
         resolution, they were observed to be closely spaced doublets.
         This was the first experimental evidence for spin.
         
     Wave particle duality

     1. An important thing to remember is this is not exhibited by 
         macroscopic objects. If the De broglie formula is used, we get                a value for wavelength which is not possible.

     

  IMPORTANT GRAPHS

         

     Orbitals

     1.  s orbitals are spherical in shape, hence it does not possess an
          angular term in the wave function.
    
     2.  p orbitals are dumbbell shaped. d orbitals are double dumbell
          shaped.
  
     3. In case of p,d orbitals , those with opposite magnetic quantum
         numbers interfere with each other to form standing waves.
         ( note that wave function(psi) also represents a standing
           wave)

     4. Angular part of all s orbitals are same.

     5. Spacing between energy levels increase as mass of particle 
         decreases and space to which particle is confined decreases.
         ( if you wish to understand the meaning of this, pl read the
           derivation of particle in a box. It is not in the syllabus!!)

     6. s orbital electrons penetrate the nucleus the most.


     Other important points: Uncertainty principle, electronic 
     configuration, Pauli' exclusion principle, Hund's rule

     Thank you for reading this post and always remember

  CHEMISTRY IS EASY

             

     

    SOME EXTRA POINTS

    

                                    CHEMICAL BONDING

    Chemical bonding is a very important part of the syllabus and
    plays an important role in understanding several other chapters
    in inorganic chemistry. Further, IIT has often asked questions 
    on this and other related chapters.

    Important Points:

   1. ORBITAL OVERLAP

    

     
     CONDITIONS FOR RESONANCE:

     1. Identical arrangement of atoms.
     2. Same number of unpaired electrons.
     3. Similar energy content.
     4. Planar.
     5. Delocalisation. 
     
     
     FEATURES OF HYBRIDIZATION:

     1. No of hybrid orbitals=No of atomic orbitals
     2. Equivalent in shape and energy.
     3. More effective in forming stable bonds.
     4. Directed in space in a preferred direction to reduce repulsion.

    
    CONDITIONS FOR HYBRIDIZATION:
   
     1. Promotion of electron is not essential.
     2. Both fully filled and half filled orbitals can take place in
         hybridization.

    
     HYDROGEN BONDING- CONSEQUENCES

    1. Higher boiling points of H2O , NH3, HF.
    2. Increase in melting point, boiling point,solubility and viscosity
        of many compounds.
    3. Viscosity of Phosphoric acid and Glycerol.
    4. Dimer formation in carboxylic acid and hexamer formation
        in HF.
    5. Negative azeotropy of mixtures of HF with water.
    6. Ice is less dense than water - When water freezes, water
        molecules form a crystalline structure maintained by hydrogen
        bonding. The orientation of these bonds causes molecules in 
        ice to move apart from each other.


     POLARIZATION:

     1. Cation should be small and anion should be large.
     2. Both should have high charge.
     3. Cations with pseudo inert config have higher polarizing 
         power.
     4. Pseudo > non inert > inert
     5. Polarization is proportional to acidic character.
     6. Polarization is proportional to color intensity.

    
     VSEPR THEORY:

     

     
    
       MOLECULAR ORBITAL THEORY

 
 

     

   
       MISCELLANEOUS POINTS:

       1. More electronegative element prefers to stay at axial 
           position whereas lone pair prefers to stay at equatorial
           position( only for TBP).

       2. % of p character is proportional to length and thinness of
           bonds.% of s character is proportional to repulsion.
    
       3.  The more electronegative element prefers to stay in the 
            orbital having more p character and it also increases p 
            character in the attached orbital.

            eg.  In  CH2F2 the C-F bond has more p character and is
            longer than C-H bond. Hence C-H bonds repel each other
            more and H-C-H bond angle is greater than F-C-F.

       4.  Back bonding: In molecules like NCl3 and Cl2O, the bond
            angle is greater than expected. This is due to back bonding
            which can be thought of as donation of a lone pair from
            the central atom into empty orbitals.


            These were the important points in Chemical bonding. I 
            hope that these will help you. Always remember 
                                             
                                 CHEMISTRY IS EASY

                                        THANK YOU.
            

                                   GASEOUS STATE

     Gaseous state is the second physical chemistry topic in the jee 
       advanced syllabus. It remains an important chapter despite
       the lower weightage given to it by iit's.

       In this chapter, numericals generally turn out to be easy. 
       Hence one must focus on the theory and graph analysis.

       Some important points:

       1. Boyle's law and Charles's law are examples of limiting laws,
           a law that is strictly true as pressure tends to 0.
       2. An ideal gas is one in which there are no interactions.
       3. P = p1 + p2 + p3 +..... ( true for real and ideal gases which
               are non reacting and at equilibrium.)
       4. However, only in case of an ideal gas, the pressure exerted
           on the walls is equal to partial pressure.
       

       Kinetic theory of gases:
   
       1. It is valid when the diameter of molecules is much smaller
           than mean free path.
       2. Gases are highly compressible.
       3. No force of attraction at ordinary temperatures.
       4. Collisions are perfectly elastic.
       5. Density is constant in all parts of the container.
       6. No of collisions per unit volume is constant.

  
       Real Gases:
     
       1. Repulsive interactions occur only when distances are very
           small.
       2. Attractive forces have a longer range.
       3. Van der Waals constants are given symbols " a" and "b".
         4. "a" depends on temperature but "b" does not.
       5. Real gases behave like ideal gases when temperature is
           high and pressure is low.
       6. Larger value of "a" implies that the gas occupies lesser
           volume due to more attraction.
       7. Smaller value of "b" implies greater compressibility.
         8. Compressibility Factor - "Z". When Z>1, repulsive 
           forces dominate. When Z<1, attractive forces dominate.

         
     a useful link for information on real gases


        NOTE:  Do revise ncert in this chapter and concentrate on 
                     the CO2 isotherm.

      Miscellaneous points: 
      
      1. Vapour pressure is constant at a given temperature.
      2. Joule Thompson effect is not part of the syllabus but those
          interested can find the required information in the link
          given below.

          https://www.comsol.co.in/multiphysics/joule-thomson-effect

   
        
                                    THANK YOU

     

      

                GENERAL TOPICS IN PHYSICAL CHEMISTRY

     The syllabus in physical chemistry starts with this topic. The
     following are few of the important points in general physical
     chemistry.

     
       Dalton's atomic theory:
    
     1. Matter consists of indivisible atoms.
     2. All atoms of a given element have identical properties.
     3. Compounds are formed when atoms of different elements
         combine in a fixed ratio.
     4. Chemical reactions involve reorganization of atoms. 
     5. Atoms are neither created nor destroyed.

   
      Mole concept: 

     1. In any question always check if a reactant is a limiting
         reagent.

     2. No of molecules = No of moles* Avogadro No.
         No of atoms= molecularity* no of molecules.


     Balancing Redox Reactions:

     By jee advanced, all of you will be thorough with this topic. 
     
     Oxidation Number:

     1. It represents real charge in case of ionic compounds but
         imaginary charge in covalent compounds.
     2. Metals can have negative oxidation number in metal 
         carbonyls like [Ni(CO)4]-

     3. In SCN-  oxidation state of carbon is +4 sulfur is -2 and
         nitrogen is -3.

     4. In salts n factor is the total positive charge or
         the total negative charge.


    There is nothing much to revise in general physical chemistry.
    During the course of your preparation, you will definitely come
    across questions based on oleum, back titrations and double
    titrations etc. These topics have not appeared in iit jee for
    a long time. However, during iit preparation, do practice a 
    few questions from these topics. 

    Past trends in iit jee indicate that one can easily score full
    marks in general physical chemistry.
   

                                    THANK YOU
        
     

      

     

                                                  CHEMISTRY FOR JEE

    This post will give a brief overview on how to prepare for jee
      chemistry and the books mentioned should be used in a                         sequential order. 

      Jee mains: The only book required is class 11 and class
      12 ncert books. One must be thorough with these 2 books and
      concentrate on chapters like environmental chemistry, polymers
      and everyday life chemistry. This will assure you of a mark of                 more than 100 in chemistry.

     Jee Advanced: This exam requires a more comprehensive 
     knowledge and deep understanding of the subject. Always 
     remember to keep the syllabus next to you while studying
     chemistry and stick to it.

   1. Physical chemistry: Recent trends in jee show that conceptual
       and graph based questions are getting increasing weightage.
       For eg. the solid state question in paper 2 and the surface
       chemistry question in paper 2 ( both in 2016).

       Recommended books:

      1. Ncert ( class 11 and 12)
      2. Course material from institutes
      3. Physical chemistry by P.Bahadur
      4. Physical chemistry by Atkins ( the kinetics question in                             2016 was directly taken from this book).
      5. Problem solving from Awasthi and Jaiswal. 
      6. Notes from my blog(of course)

   This is a general list and needs to be modified based on a 
   student's needs and dreams.

   2. Organic Chemistry:  This generally turns out to be the easiest
       section in the paper. However the organic part in the 2016
       paper turned to be much tougher than expected. So one can
       expect a similar level in the future.


      Recommended Books:

    1. Ncert ( class 11 and 12)
    2. Course material from institutes.
    3. Organic chemistry by clayden 
    4. Organic chemistry by Jerry March

    In the past questions have been directly asked from books 3
    and 4 in the above list. I will be including most of the important 
    points from these books so a quick glance should be enough.

    Most of the popular practice books have many irrelevant 
    questions and one need not attempt such questions.

    Isomerism seems to be difficult for most students and requires
    both theory as well as practice.( concentrate on this). Further,
    do not neglect practical organic chemistry.


  3. Inorganic Chemistry:  The most feared part of chemistry and
      the reason most hate the subject. There is no sugarcoating 
      the fact that one has to memorize a lot. However, i hope to 
      remove your fear or at least help you to score well.

      Firstly, the ncert textbooks are the holy books for inorganic
      chemistry. Most teachers and institutes teach much beyond
      the required level. If one analyses the 2016 paper, more than
      80% of the inorganic part can be solved by reading ncert.

      Hence, one must be thorough with all the trends and reactions
      in the ncert books.

      Other Recommended books:

     1. Inorganic Chemistry by JD Lee.
     2. Puri and Sharma ( only for coordination compounds)
     3. Chemical Bonding by Disha Publications.
     4. Salt Analysis by Vogel
     5. This blog( My chemistry professor gave extensive notes
          for inorganic chemistry which i will be posting here)

     PS: I scored 90% in iit jee inorganic chemistry.


     Thank you all for reading this long post. Always remember
     ' CHEMISTRY IS EASY'.
     
 

       
    


   

                                                      INTRODUCTION

   Hello everyone and welcome to my blog. I am Surya Suresh                  and this blog is my attempt at making chemistry easier for all

   the jee aspirants out there. Chemistry remains the most crucial 

   part of jee advanced as well as the most scoring. Despite this                many students develop a dislike for subject and even fear it.

   With the help of this blog i hope to extinguish your fears and 

   help you improve your marks in chemistry.

   My plan for this blog is as follows:

  

   1. I will initially post revision notes for all chapters. This

       helped me greatly during the last few months of my

      preparation. I hope that these notes will help you all to 
      quickly revise topics before your chapter tests.

   2. I will slowly add to these notes so that this blog serves as                      a repository of information for all things chemistry by 
       jee 2018.

          

   3. I will try to add question papers and practice problems                            whenever possible.

   4. All readers are free to send their questions through email and                i will answer them to the  the best of my ability.

          

 This is my first post and i thank all the viewers. i hope to add much more in the future and help all  iit aspirants achieve their dream ranks.