Can anyone help me get a better idea of the molar mass concept and please don't give me a copy paste answer i have checked many websites already ?

1 Answer
Feb 9, 2015

As I'm sure you've already read, molar mass expresses the weight of one mole of a substance (or compound).

Think of it like this. One mole of any element has exactly #6.022 * 10^(23)# atoms, also known as Avogadro's number. However, the weight of a single atom varies across the periodic table because of the increase in atomic number, i.e the number of protons an atom has in its nucleus.

This is why the molar masses of heavier elements are bigger than the ones of lighter elements. You still have the same amount of atoms present, #6.022 * 10^(23)#, but now each individual atom weighs more, which implies that 1 mole of those atoms will weigh more.

Imagine you have something like a basketball team. Five players. This will represent 1 mole of players. As you expect, if you compare a team of elementary school kids with a team that plays in the NBA, the "molar mass" of each team will be different.

Five elementary school players will have a lower "molar mass" when compared with the NBA team because of the difference in weight between each individual member of the team.

This is what molar mass essentially means - how much a "team" of atoms weighs for a particular element. The same idea is true for compounds - the molar mass of water, for instance, expresses how much #6.022 * 10^(-23)# molecules of water weigh.