Firstly let us discuss what are optically active compounds? These are the compounds that rotate the plane of polarized light. Now Diastereomers are basically mirror images of two optically active compounds. They rotate the plane of polarized light, either to the left side or to the right. If they are present together, they cancel theContinue reading “Why the diastereomers of optically active compounds are optically inactive?”
Category Archives: chemistry
What is the difference between molecular mass and formula mass?
In case of ionic compounds we have crystal lattice composed of ions. And there is a never ending pattern of ions and that made it difficult to calculate the molecular mass. Thus we used a simple method by taking the ratio of the ions and then adding their masses, like in case of NaCl ;Continue reading “What is the difference between molecular mass and formula mass?”
What are the characteristics of pure substances in points?
Here are the characteristics of pure substances They are composed of same kind of particles. Can not be solved into its components by physical method. Have characteristic melting and boiling points. All the particles or the bulk show similar chemical and physical behavior.
What is the difference between stereoisomers, optical isomers and enantiomers?
Stereoisomers :- These are the compounds that have same molecular formula but different arrangement of atoms in the space. Optical isomers :- The compunds that have same molecular formula but they rotate the plane polarised light to the different side, right side-dextrorotatory and left levorotatory. Enantiomer :- These are the compounds that are mirror imagesContinue reading “What is the difference between stereoisomers, optical isomers and enantiomers?”
What is a racemic mixture?
On the basis of Optical activity the compounds or isomers can be classified into two types:- Those rotate the plane polarised light towards right called the dextro rotatory compounds. Those rotate the plane polarised light towards left are called Laevo rotatory compounds. The equimolar composition of the above two isomers is called racemic mixture.
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?”
What is the hybridisation of Cl2? Is it different from the hybridisation of F2 molecules?
Here you can see the hybridization of both is same , both of these two elements have seven electrons in outermost shell and below is the diagram showing the electrons filled in s-subshell and p-subshell . one orbital of s- subshell and three orbitals of p-subshell are used during hybridisation. So the type of hybridizationContinue reading “What is the hybridisation of Cl2? Is it different from the hybridisation of F2 molecules?”
What will be the volume of water when it is heated from 0 degrees Celsius to 10 degrees Celsius?
According to CHARLES LAW “At constant pressure, The volume of a given mass of a gas increases or decreses by 1/273 of its volume at 0 ͦ degree C for every one degree centigrade rise or fall in temperature”. Vol at 10 = vol at zero + 10 x vol at zero/273
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?”
Why methanoic acid is stronger than ethanoic acid?
In case of methanoic acid the carbon atom joined to the carboxyl group is attached to only hydrogen atoms which are not able to increase the electron density. HCOOH But in case of ethanoic acid we have a methyl group attached to the carbon of carboxyl group , which is electron releasing group and itContinue reading “Why methanoic acid is stronger than ethanoic acid?”
How does the normality of a mixture equation change for different solutes?
Actually normality depends upon a simple formula that is :- Normality = Number of Gram equivalents / litre The term gram equivalents change as the valency of a substance changes . all the elements do not have same valence and hence it varies from element to element or molecule to molecule. And the term gramContinue reading “How does the normality of a mixture equation change for different solutes?”
What is a chemical bond ?
Chemical bond may be defined as the force of attraction by which two atoms are held together. The chemical bonds lead to the formation of molecules and crystals. There are various kind of bonding that we see around us. Covalent bond A covalent bond is formed by mutual sharing of electrons between two atoms. ForContinue reading “What is a chemical bond ?”
What are the ions produced when sulfuric acid ionises?
sulfuric acid ionizes to give us hydronium ion and sulfate ion. H2SO4 (aq) → 2H+ + SO4
Neutralisation reaction
The reaction between an acid and base to give salt and water is called neutralisation reaction. here in the following reaction we can easily see how Hydrochloric acid is reacting with sodium chloride NaOH + HCl ———> NaCl + H2O the nature of salt formed is dependent on the type of acid or base , ifContinue reading “Neutralisation reaction”
Atomic models
Thomson’s model of an atom Thomson proposed the model of an atom to be similar to that of the Christmas pudding. Thomson proposed that An atom consists of a positively charged sphere and electrons are embedded into it. The negative and positive charges are equal in magnitude so the atom as a whole is electricallyContinue reading “Atomic models”
Atomic Structure
Dalton’s Atomic Theory In 1808 John Dalton published a new system of chemical philosophy in which he propose the following theory :- Matter consist of indivisible atoms. All the atoms of a given element have identical properties. Compounds are formed when atoms of different elements combined in a fixed ratio. Chemical reactions only involve theContinue reading “Atomic Structure”
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.”
A Short intro to acid, base and indicators.
Acid base and salts Acids:- these are the substances that Are sour in taste. Turn blue litmus red. Give H+ ions. Can accept a pair of electrons. Base :- These are the substances that Are bitter in taste. Turn red litmus blue. Soapy in touch. Give OH– ions. How to recognise the acid and bases?Continue reading “A Short intro to acid, base and indicators.”
Basics of chemical reactions and chemical equations.
Chemical Change The change which give rise to new substances with new properties that are totally different from the starting matter. 2H2 + O2 ———> 2H2O Chemical changes are normally accompanied by the following changes:- 1. change in state 2. Change in colour 3. Change in temprature 4. Evolution of gas Chemical reaction RepresentationContinue reading “Basics of chemical reactions and chemical equations.”
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?”
The Unconditional Guru 