Tag Archives: can

What is myopia near sightedness class 10th cbse pseb board classes

This is a type of eye defect Near sightedness or Myopia is a defect of eye in which the objects present near can be seen clearly but the far ibjects can not be seen by the person suffering from this disease. It can arise due to the following reasons :- 1. Increased length of eyeContinue reading “What is myopia near sightedness class 10th cbse pseb board classes”

How we can prepare Phthalic acid from ortho xylene by oxidation?

It is a two step reaction in which 1. di-alkyl benzene is oxidised 2. In step two , the acidic environment helps in providing the Hydronium ions and they easily get converted into a carboxylic acid . Phtahlic Acid is used in various kind of preparations and has a vast industrial applications. In this reactionContinue reading “How we can prepare Phthalic acid from ortho xylene by oxidation?”

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. Intermolecular hydrogen bonding takes place between two molecules having hydrogen and electronegative element. Hydrogen is attracted by the electronegative element of another molecule for exampleContinue reading “What is hydrogen bond? How does an intermolecular hydrogen bond differ from intramolecular hydrogen bond ?”

Organic inter-conversions , Propene to 1-nitropropane,ethane to bromoethane, ethanol to but-1-yne, Propene to propyne, toluene to benzyl alcohol.

Why is carbon important for forming complicated molecules? Or why carbon makes a large number of molecules ?

The answer to this question is very simple . There are two major reasons behind it. 1. Catenation :- It is the property by which the carbon can make long chains, branched chains and ring or cylic structural by joining with its own atoms. Due to this it can make a variety of molecules. 2.Continue reading “Why is carbon important for forming complicated molecules? Or why carbon makes a large number of molecules ?”

Why ortho-nitrophenol is more acidic than ortho-methoxy phenol ?

To answer this we have to see the reactive nature of phenol and the substituents attached to it. Acidic behavior of phenol depends on the fact that how easily it can loose a proton and make phenoxide ion which is stabilized by resonance. The methoxy group being electron donating group increases the electron density ofContinue reading “Why ortho-nitrophenol is more acidic than ortho-methoxy phenol ?”

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. The reaction is named after the Swiss Chemist Traugott Sandmeyer. In this reaction the diazonium group losses the molecule of dinitrogen and it yields chlorobenzene.

Explanation of Schottky defect, Frankel defect, Interstitial defect and F-centres.

1. Schottky defect:- In this kind of 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 ofContinue reading “Explanation of Schottky defect, Frankel defect, Interstitial defect and F-centres.”

What are the methods of preparation of Aldehydes and Ketones ?

[SiF6]2- exist but [CF6]2- does not, why?

A nice question both silicon and carbon belong to group 14 and have 4 electrons in the outermost shell. Their general valency is 4 , but silicon and other elements show higher oxidation states also. Only carbon is the element in group 14 elements that do not have vacant d-orbital. All other elements like siliconContinue reading “[SiF6]2- exist but [CF6]2- does not, why?”

How does phosphorus form 5 covalent bonds?

The number of valence electrons in phosphorus is generally 5 and it requires 3 more electrons to complete its octet. but it has an empty d-sub shell in which its electrons can excite and increase its valency from 3 to 5. in the above picture you can easily understand in case of phosphorus , theContinue reading “How does phosphorus form 5 covalent bonds?”

What are some of the most efficient methods of preventing rusting?

Here are the five ways:- Paint the surface of metal. Oil the surface of metal or keep it covered with grease. Electroplating it with a less reactive metal will keep it safe. Galvanisation that is covering it with Zinc metal it is also called sacrificial protection. Making it cathode, most of the underground pipes areContinue reading “What are some of the most efficient methods of preventing rusting?”

How many atoms are there in 1 gram of carbon?

For  calculation of number of atoms we have to calculate the number of moles present in 1gram carbon. Multiply the number of moles with Avogadro number. Step I  Number of moles in 1 gram of carbon = given mass / molar mass Molar mass (molecular or atomic mass expressed in grams) = 12g So theContinue reading “How many atoms are there in 1 gram of carbon?”

How many oxygen atoms are there in 90g of H2O molecule?

1 molecule of H2O has 1 atom of oxygen. Firstly we will calculate the number of atoms in 90g of H2O. we will explain it in two steps:- Step I:- No.of moles of H2O = given mass / molar mass No. of moles = 90/18 = 5 moles No. Of molecules = No. of molesContinue reading “How many oxygen atoms are there in 90g of H2O molecule?”

What is the number of moles of O-atom in 126 AMU of HNO3?

Here we have 126 AMU of HNO3, Molar mass of HNO3 is 1+14+16×3 = 63amu Number of molecules of HNO3 are = 126/63 = 2 Here we have 2 molecules Each molecule have 3 atoms of oxygen. So no. of oxygen atoms= 3×2 =6 atoms No. Of moles = given particles/ avogadro number No. ofContinue reading “What is the number of moles of O-atom in 126 AMU of HNO3?”

Various separating methods

We come across the various kind of mixtures in our daily life that have different kind of components and sometimes we have to separate the components for our benefit and there comes the need of separation in our day to day life.  we do separation by using different kind of separating techniques. some techniques AreContinue reading “Various separating methods”

Distillation and fractional distillation.

Distillation is a type of separating process in which two miscible liquids are separated from each other by using their different boiling points. the one with lower boiling point , boils first and its vapours are passed through a condenser for cooling and droplets are received on the other side in a beaker. this processContinue reading “Distillation and fractional distillation.”

what is valency ? how to calculate it?

Valency :- “It is the combining capacity of an atom”. it also indicates the number of electrons that can be gained , lost or shared . It decides that how many bonds can be formed, it gives the idea of molecule formation and the type of bond formed. calculation of valency is a simple taskContinue reading “what is valency ? how to calculate it?”

Full explanation of mole concept.

The word mole means pile up . This concept originated from a simple problem that was faced by the scientists to calculate the reactions. they needed a concept that could relate number of molecules with the weight. A mole of a substance is equal to as many molecules of that substance as there are numberContinue reading “Full explanation of mole concept.”

How to balance the chemical equation?

The need of balancing the chemical equation. The law of conservation of mass , “ Mass can neither be created nor be destroyed during any chemical change”. So the number of atoms on both RHS and LHS must be equal in the chemical equation. We have to check the total number of atoms on RHSContinue reading “How to balance the chemical equation?”