Answers

 

Explanation

When calculating the molecular mass of a compound, remember that the M_r of H=1, C=12, N=14 and O=16.

With respect to naming a compound from the formula, or the other way round, meth- =1 carbon atom in the backbone, eth- =2, prop- =3, but- =4, pent- =5 and so on. An "-ol" tells you that there is an alcohol group in the structure, and the number (e.g. (2)) tells you which carbon of the backbone the -OH group is attached to. If the molecule is a primary alcohol, (i.e. the -OH is attached to carbon 1), the number is not written. If the -OH isn't attached to the carbon 1, but one of the carbons within the chain, the molecule is a secondary alcohol. An "-oic" acid is a carboxylic acid group, "-dioic" acid means two carboxylic acids groups. Remember that there is also information within the middle of the name. "an" (such as in propane) means that there are no double bonds, whereas "en" (propene) tells you that there is a double bond between two carbons, and so two less hydrogen atoms in the molecule.

Remember that if you use Greek letters to 'number' the carbon atoms in a molecule, a = 2, b = 3, g = 4 and so on. Hence a-oxoglutarate = 2-oxoglutarate, b-hydroxybutyrate = 3-hydroxybutyrate, g-aminobutyrate = 4-aminobutyrate.