A sample of ethanol, C2H6O, contains 1.25 mol of the compound. Determine the amount (in mol) of each element present and the number of atoms of each element present in the sample.

Ethanol belong to class of organic compounds called as alcohols. It is known as one of the green solvent used in most of the organic reactions. It has a Molecular Formula;

C₂H₅OH or C₂H₆O

In above molecular formula there are two basic terms shown'

1) Symbols:

Symbols are the chemical notations representing the said element with one or two characters. In this case the C is symbol of Carbon atom, H is symbol of Hydrogen atom and O is symbol of Oxygen atom. hence, we can say that ethanol is made up of carbon, hydrogen and oxygen atoms.

2) Subscripts:

Subscripts are the numbers in chemical formula which are written below the normal line. In molecular formula they specifies the number of said elements. For example. in ethanol the 2 after C shows that there are two atoms of carbon, the 6 after H shows that there are 6 atoms of hydrogen and no subscript after O shows that there is one oxygen atom in this molecule.

Hence, we can conclude that each mole of Ethanol contains,

2 moles of Carbon

6 moles of Hydrogen

1 mole of Oxygen

Now,

As,

1 mole of C₂H₆O contained = 2 moles of C

So,

1.25 moles of C₂H₆O will contain = X moles of C

Solving for X,

X = 1.25 × 2 mol / 1 mol

X = 2.5 mol of C

Also,

As,

1 mole of C₂H₆O contained = 6 moles of H

So,

1.25 moles of C₂H₆O will contain = X moles of H

Solving for X,

X = 1.25 × 6 mol / 1 mol

X = 7.5 mol of H

And,

As,

1 mole of C₂H₆O contained = 1 moles of O

So,

1.25 moles of C₂H₆O will contain = X moles of O

Solving for X,

X = 1.25 × 1 mol / 1 mol

X = 1.25 mol of O