What is a mole?

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The concept of a mole can be difficult to get your head around.

We are used to giving some numbers names, for example 1 million instead of 1,000,000. And we can use a million as a unit, 3 million, 60 million and so on.

A “mole” is the same concept; only the number that the word “mole” represents is far more complicated! 6.02x1023 approximately; this number is also called Avagadro’s constant. And where on earth did this random number come from? It is the number of atoms in 12g of carbon.

This is used as a reference for all particle counting.

So 1 mole of gold (Au) contains 6.02x1023 atoms and 1 mole of water (H2O) contains 6.02x1023 water molecules.

Note this tells us nothing about the weight of 1 mole of gold, or water. The atoms or molecules will have different masses, like 6.02x1023 feathers vs. 6.02x1023 hammers.


Dara A. GCSE Chemistry tutor, GCSE Biology tutor, A Level Chemistry t...

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