Hill notation is a standard way of writing the formula for any chemical compound. Hill notation is NOT unique for a compound. The empirical formula for any compound is written in correct Hill notation.
First, Count All Carbon Atoms and record. C10
Second, Count all Hydrogen atoms and record: C10H23
Third, determine all other elements in compound. Count each and record in alphabetical order. C10H23N When determining counts from a structural drawing, CAREFULLY count H atoms!!
Counting all the Carbon atoms: C6
Counting all the Hydrogen atoms: C6H18
Determining all the other elements in the compound. Count each and record in alphabetical order.
Hill order is the organization of formulas in Hill notation. It allows compounds to be methodically indexed. All compounds containing both Carbon and Hydrogen atoms have those listed first, with all other elements following, in alphabetical order. All compounds without C and H have elements listed in alphabetical order. Numbers of atoms are arranged in ascending order, so that all C2 compounds appear before any C3.
EXAMPLE OF HILL ORDER
(taken from Gary Wiggins' book)