Question

I hope anyone will answer for my question.. my question is define mole concepts?

Answer 1

The mole is the unit of measurement for amount of substance in the International System of Units (SI). The unit is defined as the amount or sample of a chemical substancethat contains as many constitutive particles, e.g., atoms, molecules, ions, electrons, or photons, as there are atoms in 12 grams of carbon-12 (12C), the isotope of carbon with standard atomic weight 12 by definition. This number is expressed by the Avogadro constant

Answer 2

When dealing with particles of the size of atoms and molecules, it becomes very difficult to do the calculations as they are present in very large numbers. Even in a small sample of an element or chemical compound, generally the number of elementary particles are in the higher order of 10. So to make these calculations simpler, mole was defined. While solving problems, the numbers are expressed in terms of Avogadro number, making the solution to the problems in physical chemistry simpler.


 the mole concept can be used to do various other calculations as shown :

Formulae to calculate the no. of moles –

Number of moles of molecules = wt. in gm / molecular mass

Number of moles of atoms = Wt. in gm / atomic mass

Number of moles of gases = Volume at STP / Standard Molar Volume (Standard molar volume at STP = 22.4 lit)

Number of moles of particles e.g. atoms, molecules ions etc = No. of particles / Avogadro number