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Chemistry 130
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Related Links
Molecular Formula Search Tips
To search by molecular formula, first summarize the line formula and then arrange
elements in Hill System Order.
| Line Formula |
Summarized Formula |
Hill System Order |
| BrCH2COOH |
C2H3O2Br |
C2H3BrO2 |
Definition of Hill System Order
- Carbon first, Hydrogen second, and all remaining elements, including deuterium and
tritium, in alphabetical order
- If no carbon is present, put all elements in alphabetical order
- Indicate the number after each element (ignore the fact that the numbers
are subscripts)
Case-Sensitivity of Element Symbols
- While the molecular formulas of most resources on campus are not case-sensitive
(element symbols may be typed in either upper or lower case letters), the element
symbols ARE case-sensitive in:
- Chapman and Hall Chemical Dictionaries on CD-ROM (Organic Compounds,
Natural Products, and Inorganic & Organometallic Compounds)
- INSPEC (molecular formulas are put in the Chemical or CH Index)
- For example, in the formula above, Bromine would need to be searched as Br.
