General Formula: Alcohols is CnH2n+2O but molecular formula for alcohol is CnH2n+2O. Carboxylic
acid is CnH2nO2. Ketones is CnH2nO. Cycloalkane is CnH2n. If asks for molecular formula, can’t have
OH on the end.
• Structural Formula: Usually CH3 at either ends. CH2 in middle unless functional groups e.g. CHBr
or BrBr. If same two molecules together, group together. May or may not include CH=CH if alkene.
• Write in order as carbon appears and then add the H or functional groups on.
• In structural, don’t write as C2H6, but CH2CH3.
• When on same carbon and in the middle, will have brackets e.g. CH(OH).
• Skeletal Formula: End of line–CH3 group. Double parallel line is double bond. Methyl group is just
line should be same length. Do a line and name functional groups, however line does not mean a
CH3 group as has functional group on it.
• Alicyclic drawn with two H atoms going out.
• If ester or an atom in between C atoms. Put O in ester, cutting the line.
• If more than one side group on a C, e.g. CH2CH3, continue the lines zigzagging downwards.
Molecular Formula: Collect all elements together. Will be three around any ends of line. 2 on
either side of straight chain unless functional groups.