Dear student ,
Mole concept is a very basic topic of chemistry. It should be clear enough to even solve the questions of other related chapters.
Mole is the counting unit of chemistry .
1 mole of any substance = 6.022 * 1023 species or entities
= This is known as Avogadro’s number or Avogadro’s constant ( denoted as NA or No )
Note : these species can be atoms or molecules or ions or electrons or protons , etc.
Now question arises from where we get this value of 1 mole ?
Definition of 1 mole : 1 mole is defined as the no. of atoms present in 12 gram of C-12 isotope.
Let us take some examples :
(i) 1 mole of Mg atoms = 6.022 * 1023 Mg atoms ( you can imagine it is such a large no. of atoms of Mg, so it is rather easy to say 1 mole of Mg )
(ii) 5 moles of Mg atoms = 5 * 6.022 * 1023 Mg atoms
(iii) 1 mole of CO2 molecules = 6.022 * 1023 or NA molecules of CO2
(iv) 4 moles of NH4+ ions = 4NA ions of NH4+
Hope it is clear now. Still if you have further queries you can ask.
Chemistry Consultant
Askiitians
