INTRODUCTION:
In chemistry, compounds can be distinguished by using the empirical formula. The formula provides the simplest positive integer ratio of elements in a compound. The empirical formula is largely useful in determining the ratio of elements within ionic compounds where the structure is of a non-directional nature of bonding where any ion at any time could be surrounded by 4, 6, or 8 oppositely charged ions. This creates a pattern of endlessly repeating lattice of ions they do not exist as a free unit of atoms but in crystal lattices with repeating ions in specific ratios which is why empirical formula is used as a form of identification for defining an ionic-bonded substance.
Calculating the empirical formula:
To calculate the empirical formula for when two reactants undergoes a chemical reaction, the following 5 steps should be taken:
1. Record the masses of all the elements present in a given compound.
2. Convert the masses into moles (dividing by atomic weight in grams).
3. Then divide through by the smallest number of moles to get a ratio.
4. It the numbers are not whole numbers, multiply by a suitable small factor to get a whole number.
5. Finally, round off the numbers in the previous step if applicable to get the prime numbers which indicates the empirical formula.
To demonstrate with a simple example; The molecular formula of butane is C4H10, however as the ratio of carbon atoms to hydrogen atoms is 4:10; it can be reduced to the ratio of 2:5. We can see that it is the simplest ratio while remaining as an integer. Butane can now be represented in empirical formula as C2H5.
Regarding the Mole and its formula:
The mole is the quantity of a substance which contains as many elementary units (atoms, ions, molecules) as there are atoms in exactly 12 grams of carbon-12 isotope.
A mole of an element is