Why is the molecular formula of a gas not necessarily the same as its empirical formula?
answered above.
The molecular formula of a gas is not necessarily the same as its empirical formula because the molecular formula represents the actual number of atoms of each element in a molecule, while the empirical formula represents the simplest whole number ratio of atoms in a compound.
To understand this concept, you need to know the difference between the molecular formula and the empirical formula. The empirical formula simplifies the molecular formula by dividing the number of atoms of each element by their greatest common divisor. This reduction results in the simplest ratio of elements in a compound.
For example, let's take a compound with a molecular formula of C2H4 (ethylene). The empirical formula of ethylene is CH2 because dividing the subscripts by 2 gives the simplest ratio of carbon to hydrogen atoms.
In other cases, the molecular formula and empirical formula might be the same. For example, a compound like H2O (water) has a molecular formula that is already in its simplest ratio, so the molecular formula and empirical formula are identical.
In summary, the molecular formula of a gas may not be the same as its empirical formula because the molecular formula represents the actual number of atoms in a molecule, while the empirical formula represents the simplest ratio of atoms in a compound. To find the molecular formula from the empirical formula, you would need additional information about the actual number of atoms in the molecule.