How do you derive chemical formulae from experimental data?

Chemical formulae are derived from experimental data by determining the ratio of elements present in a compound.

To derive a chemical formula from experimental data, you first need to understand the composition of the compound. This involves identifying the elements present and their respective quantities. This can be done through various experimental methods such as spectroscopy, mass spectrometry, or chemical analysis.

Once you have identified the elements and their quantities, you can then determine the ratio of these elements. This ratio is crucial in deriving the chemical formula. For example, if a compound is found to contain 1 part hydrogen and 2 parts oxygen, the chemical formula would be H2O, which is the formula for water.

However, it's important to note that the ratio must be in the simplest whole number form. If the ratio is not a whole number, it must be converted. For example, if a compound is found to contain 1.5 parts hydrogen and 1 part oxygen, the ratio would be converted to 3:2, giving the formula H3O2.

In some cases, the molecular formula (which shows the actual number of atoms of each element in a molecule) may be different from the empirical formula (which shows the simplest whole-number ratio of atoms in a compound). For example, the molecular formula for glucose is C6H12O6, but its empirical formula is CH2O. To determine the molecular formula from the empirical formula, you need to know the molar mass of the compound, which can be determined experimentally.

In conclusion, deriving chemical formulae from experimental data involves identifying the elements present in a compound, determining their quantities, and then expressing these quantities as a ratio in the simplest whole number form. This ratio then forms the basis of the chemical formula.