Go to ...

PHYSICS TEACHER

Physics Fundamentals BLOG for K12

RSS Feed

Difference between mole and molecule-mol or mole vs molecule


Difference between mole and molecule – mole vs molecule

Keywords covered in this post are are mole or mol, molecule, gram mole, g mol, gram mol, molar mass and mole vs molecule . While studying the chapter on gas laws you must have come across the term ‘mole’ or ‘mol‘. You may have seen gram-mol as well in that chapter. I find many students confused with mole (or mol) and molecule. Here we will discuss and explain the concept of mole or mol with some examples. We’ll also go through a quick definition of molecules. This will help you to understand the difference between mole and molecule.



Mol or Mole ? Mol vs Mole? Any difference between mol and mole?

Any difference between mol or mole? A big NO. Remember that mole and mol are synonymous. (same thing). So we can use either mol or mole to refer to that stuff (to be discussed in the para below). But to note that molecule is different from mole or mol. So lets discuss the concepts in the next section.

Mole or Mol – Concepts

One mole (also abbreviated as mol) is the amount of substance that contains a specific number of particles ( 6.023 X 1023). These particles may be atoms or molecules or ions etc.

Just to simplify, 1 mole of sand means a sand sample where 6.023 X 1023 number of sand particles are there.

So if we say 1 mol of Oxygen gas, then that means an amount of Oxygen sample which contains 6.023 X 1023 number of Oxygen molecules. (in gas form of Oxygen is available in molecules)

Similarly 1 mol of atomic Carbon contains 6.023 X 1023 number of Carbon atoms. (in atomic form of Carbon, it is available in atoms)

This specific number (6.023 X 1023 ) is called Avogadro number.

Difference between mole and molecule – Mole vs Molecule

If you already have the concept of molecules, this concept of mole or mol we just discussed above will certainly help you to understand the difference between mole and molecule.

Otherwise to brush up, I am adding a definition of molecule here:

Definition of a molecule: A molecule is the smallest particle in an element or compound that possesses the chemical properties of that element or compound. Molecules are made up of atoms that are again held together by chemical bonds.

Summary: Now we know that a Mol or Mole may contain particles of atoms or molecules or ions etc. of certain specific number.
But Mol (or Mole) is an entirely different concept from molecule and you should understand their differences as you go through this post!

Gram-mole: representation of  molar mass in gram

1 gram mole of Oxygen gas:

Oxygen gas exists in molecular form in the nature.

So in this case we have to count the molecular mass of Oxygen( O = 2X16) and add the gram unit with it to get the mass of 1 gram mole Oxygen.

So 1 gram mole Oxygen gas means 32 grams of Oxygen gas.

Now 1 gram mole atomic Carbon:

Carbon is available in atomic form.

So in this case we have to get the atomic mass of Carbon (C = 1X12) and again add the gram unit with it.

So 1 gram mole atomic Carbon means 12 gram Carbon.

As water (steam/vapour) is available in molecular form, so 1 gram mole water (H2O) means 2X1+16 that is 18 gram of water molecules.

Gram mole and Avogadro number

So we can say that 32 grams of Oxygen gas will contain Avogadro number (6.023 X 1023) of Oxygen molecules.

Similarly 12 grams of atomic Carbon contains Avogadro number (6.023 X 1023) of Carbon atoms.

And 18 gram of water molecules will contain Avogadro number (6.023 X 1023) of water molecules.

**Remember that (6.023 X 1023 ) is called Avogadro number.



Sample problems:

Q1. Find out the the number of moles in 132 gram of CO2.

Solution:

Molar mass of CO2 = gram molecular mass of CO2 as it is available in molecular form = [12 + 2X16] gram = 44 gram.

we know, total mass of the sample = mass per mole X number of moles = molar mass X number of moles

so, number of moles (n) = mass of the sample / mass per mole = 132/44 =3

Q2. Find out the number of molecules in 8 gram of Oxygen.

 Solution: you can try and do it yourself. (Ans: 1.506 X 10^23 molecules)

Suggested Post: physics problems

wiki – molecule

Tags: , , , , , , , , , , , ,

2 Responses “Difference between mole and molecule-mol or mole vs molecule”

24 Shares
+1
Tweet
Share2
Share
Pin
Stumble22