Stobbe reaction and its Mechanism
It is a type of condensation reaction that involves the condensation of an aldehyde or ketone with succinic ester in the presence of sodium ethoxide or Potassium ethoxide to yield […]
How the age of mummies , dead bodies and fossils is calculated?
The aging of different organisms is mainly calculated by the special technique called the Radiocarbon dating. In this technique the age of any specimen is calculated on the basis of […]
Why does copper turns green on exposure to air ?
This happens because of corrosion of copper , as the copper is exposed to air it reacts slowly with water from the moisture present in air, carbondioxide and oxygen. And […]
How many lone pairs of electrons are on the S atom in sulphur tetra floride (SF4) ?
In case of SF4 there are 6 electrons in the outermost shell of Sulphur, out of these 6 electrons, 4 are utilized in bonding with fluorine and thus two unshared […]
Why is Krypton larger in size than bromine,even if atomic radius decreases while going from left to right across a period?
the atomic size of Krypton is larger than Bromine.
What is hydrogen bond? How does an intermolecular hydrogen bond differ from intramolecular hydrogen bond ?
Actually the hydrogen bond is simply a type of attraction which is caused by the the electronegativity difference between hydrogen and highly electronegative element like oxygen carbon nitrogen and fluorine. […]
What is gold number ?
It is the amount of lyophilic sol required in milligrams to prevent the the coagulation of 10ml gold sol by the addition of 1 ml, 10% NaCl solution .
Why the electron affinity or electron gain enthalpy of Chlorine is higher than Fluorine ? Even if Fluorine is most electronegative element.
chlorine shows exceptionally higher electron gain enthalpy than that of florine.
Why H3PO3 is a diprotic acid? Give reason with structure .
Meaning of diprotic acid is that , it can loose two hydronium ions (H+) . For finding how many H+ ions it can give , we have to see its […]
What is the structure of XeOF4 and XeO3 ?
The structure of XeOF4 is square pyramidal. And its hybridization is sp³d² The structure of XeO3 is pyramidal and its hybridization is sp³.
What is Wurtz reaction?
It is the reaction between alkyl halides and sodium in the dry ether to give alkanes with higher number of carbon. 2R-X + 2 Na —> R-R +2NaX
Preparation of chlorobenzene – Sandmeyer’s reaction
Chlorobenzene and bromobenzene can be prepared by treating bezenediazonium chloride with cuprous chloride or cuprous bromide. This reaction is also called Sandmeyer’s reaction.
Why sigma bond is stronger than pi bond?
Actually the sigma bond involves head to head overlapping of orbitals, due to which the overlapping takes place on a larger extent. That makes the bond more stronger as compared to pie bond. In pie bond there is a sidewise overlapping of orbitals which leads to lesser extent of overlapping and thus the bond formed is not so strong as […]
What is Raoult’s law ?
It states that for a solution of volatile components, the partial vapour pressure of each component is directly proportion to the mole fraction of the component in the solution.
What are the factors that affect Vapour Pressure?
1.Temperature :- With increase in temperature the rate of vaporization also increase thus it creates more pressure. Moreover with increase in temperature the kinetic energy of the vapours also increase. […]
Semiconductor and its types.
The substances whose conductivity lies between 10-⁶ to 10⁴ ohm-¹ . The range lies between conductors and insulators. Types 1. n-type :- These type of semiconductors have excess electrons present […]
Why glass is considered as super cooled liquid ?
It is an amorphous solid. In these kind of solids the particles are not properly arranged and it is assumed that the particles do not get enough time to set into a proper arrangement. So these are considered as super cooled liquids.
What is Coordination number
It is the number of lattice points touching one lattice point in a crystalline solid. For example in case of Sodium chloride it is 6 .
Explanation of Paramagnetism, ferromagnetism, ferrimagnetism and antiferromagnetism .
1. Paramagnetism :- This is the phenomenon by which substances are weekly attracted by the magnetic field. It arises because the substances are magnetized in the same direction of the […]
Explanation of Schottky defect, Frankel defect, Interstitial defect and F-centres.
1. Schottky defect:- In this kind 9f defect equal number of cations and anions are missing from the crystal lattice. Due to this the vacant sites or the holes are present in the lattice. This kind of defect is present in the ionic compounds with high coordination number and equal size of ions. Density of the crystal lattice decreases due […]
Why we have to provide activation energy for completion of a reaction?
To understand this concept we must be aware of Threshold energy or activation energy. The threshold energy or the activation energy is the minimum amount of energy that is required for the conversion of reactants into the products . According to collision theory the reactant species collide with each other to make the product. But every collision don’t bring about […]
Some important terms
1. Co-ordination number Number of spheres touching one Sphere in a close packed structure is called co-ordination number of a lattice 2. Unit cell The smallest repeating pattern in a […]
How the eye accommodates to light ?
#accomodation #of #light In our day to day life we face various exposure to light. The intensity of rays vary from source to source some are intense and some are […]
