Mols,chemicah equation?

Question

2AL(2)O(3)-----> 4AL + 3O(2)

i dont quite get the concept of mols and this chemical eq yet. Does it mean 2mols of aluminium oxide is = to 4 mols of aluminum and 3 mols of oxygen?wat does it really mean?can someone pls explain. in simple terms. thx

Answer 1

Mol (or Mole ) is used to measure how many atom are there.

Since there is so many of them, a mol represent about 6.22 x 10^23 atom (or molecule).

A molecule consist of many atom (in your case, an aluminium oxide molecule consist of 2 aluminium atom and 3 oxygen atom), which make 2 mol of Al203 contain 4 mol of AL, 3 mol of O (like molecule, just multiply to make the Oxygen molecule whole. You can write Al203->2Al+3/2 O2)

Understand ?

Answer 2

The term "mole" is a word used to represent the number 6.022 x 10^23.   It's like the word "dozen" which everyone knows mean "12".  So you could have a dozen eggs and you would have 12 eggs; or a dozen pencils and you would have 12 pencils.  You could also have 6.022x 10^23 eggs or 1 mole of eggs, or 6.022 x 10^23 pencils or 1 mole of pencils.

In a chemical equation the coefficients and subscripts are ratios that represent either individual atoms/molecules or moles of atoms/molecules.

Al203 means 1 molecule contains 2 atoms of Al and 3 atoms of O or 1 "mole" of molecules contain 2 "moles" of Al atoms and 3 "moles" of O.  In your balanced equation the coefficient "2" could mean 2 molecules of Al2O3 or 2 "moles" of molecules.  So, 2 molecules of Al2O3 would contain 4 atoms of Al and 6 atoms of oxygen.  You could also say 2 moles of Al2O3 molecules ( twice 6.022 x 10^23) contain 4 moles of Al atoms (four times 6.022 x 10^23) and 6 moles of O atoms (six times 6.0222 x 10^23).

On the product side you could interpret that to mean the reactions forms 4 atoms (or moles) of Al and 3 molecules (or moles) of O2 (which would be 6 atoms or moles of O).

It is not practical to use atoms/molecules in the real world since you can't see them, so we use the   larger quantity of "moles" that can be seen and measured in a practical lab situation.