Mole Concept in chemistry

MOLE CONCEPT NOTES

 => What is the term Mole in chemistry?

For buying or purchasing we always need some standards values. In other words, we take 1Kg of flour, 200ml of water or 1 dozen bananas. These terms are used in everyday life. But what if I want to measure the number of tiny particles present in it?

Let me explain this in detail.!

APPLICATION OF MOLE CONCEPT

Looking at a Glass of water can you tell that how many water molecules are present in it? You will probably say it is impossible to calculate the number of molecules in a glass of water. But astonishingly chemistry has an answer to this question as well.😊😊 That brings us to the concept of MOLE.

What does mole mean?😕 Its very easy.😊

1Mole of anything has 6.022times10^23 atoms or molecules or particles present inside it.

Isn't this number huge? If i have to write down the zeros this is how the number will look like : 602200000000000000000000000 

1Mole of  anything has these many particles. 

Now take a substance which has 3 times the number of particles 6.022times10^23 in it, then we will say it has 3 moles.

And what about the substance which has 8 times the number of  particle  6.022times10^23 in it? It will be moles of that substance. That's the main concept of mole of any substance.

Now to understand more, take an example of Gold:

How many atoms are there in 1 mole of pure gold?

Yes, as it has 1 mole , it will have 6.022times10^23 gold atoms in it.

Similarly, 1 mole of water will have 6.022times10^23 water molecules inside it.

For Example, a bag containing 6.022times10^23  Hydrogen atoms, then can we say that it contains 1 mole of hydrogen? The answer is,Yes! 

We have just understood the concept of mole in simple words. Now have a look on the Scientific definition of 1 mole. And what this number( 6.022times10^23) be referred to? Does this number have a special name? 

SCIENTIFIC DEFINITION OF MOLE:

In 1 mole of a substance ,the amount of substance contains the same number of atoms/molecules/particles as there are atoms in 12 grams of Carbon-12"

It tells us that the underlined parts are equal to each other. i.e; Number of particles in 1 mole is equal to the number atoms in 1 mole of C-12

what does 12 grams of carbon-12 mean?😕

Carbon-12 is one of the isotopes of carbon. 12 grams of carbon-12 is what we take as a standard. what is special about this? can you guess the number of atoms here? Yes, it's 6.022times10^23 atoms.

For example: ATOMS in 1 mole of GOLD = ATOMS in 12 grams of Carbon-12. This means 1 mole of gold has 6.022times10^23 atoms of gold

Remember that definition uses Carbon-12 as a standard. It is used to compare the number of atom/molecule/particles present in substance. But what's the mystery behind this number 6.022x10^23?

A scientist named LORENZO ROMANO AMEDEO CARLO AVAGADRO came up with this concept. I know the name is long😁. 

So, the number 6.022x10^23 is called as the Avagadro's number. It is just the number to represent quantities. It is just like we use the word PAIR for 2 and DOZEN for 12. Similary, the Avagadro's number is the ter, use to represent 6.022x1023 of any entity. 

So, when we go to the market can we say I want Avagadro's number of candies? 

Ofcourse, we can! but the problem is that the shop would not have those many candies and neither we will be able to carry them back home.

Now getting back to the concept Avagadro's number is the number used to represent quantities.But the number isso  huge that using it in our daily life is not practically possible. Then why this number exists if it has no use in our practical life? Yes, the number is not commonly use in daily life by us. However, it comes to the rescue of chemists that work with atoms, molecules, electrons and many such small entities. That is the reason why it is used to calculate 1 mole of substance.

Lets talk about one last concept!

we know that 1 mole of Carbon-12 = 12 grams of Carbon-12. That's because the 12 grams of  carbon has Avagadro's number of atoms.

Now checkout the last question to know that you have get the concept correctly or not.

What will be the mass of 1 mole of pure gold? will it be 12 grams? 

The answer is NO! beacause the number of atoms of Pure gold and Carbon-12 are same but the masses are different. Mass of 1 mole of pure gold will be definitely not equal to the Mass of 1 mole of carbon-12. Mass of 1 mole of pure gold is 196.97g. Similarly, 1 mole of pure water will have Avagadro's number of molecules but will not have mass of 12 grams. So if we take 1 mole of water and find its mass then mass will be 18.015g.