Question

What is the IUPAC name of $[Co(NH_{3})_{4}(OH_{2})I]SO_{4}$?
A.Tetraammineaquachlorocobalt(III)sulphate
B.Tetraammineaquachlorocobalt(II)sulphate
C.Tetraammine Aquario Cobaltate(III)sulphate
D.None of these

Answer 1

Hint: The IUPAC devised a set of instructions or rules that helped in naming the organic molecules. This helped scientists to derive names of the molecules which were not even discovered.

Complete answer:
- The IUPAC stands for International Union of Pure and Applied Chemistry. It has formulated some rules for the systematic nomenclature of organic compounds which are even revised later on for the uniform naming of compounds.
- The IUPAC name of any molecule consists of three parts- Prefix, stem name, and suffix.
- The rules for nomenclature are stated below:
Rule 1- The longest chain in the molecule will be the parent chain.
Rule 2- Find out all the substituents present on the carbon chain. It can be from any methyl to any alcohol substituent.
Rule 3- Start numbering the parent chain from the end such that the substituent gets the lowest number. This is called the lowest locant rule.
Rule 4- If the substituent occurs more than one time, then the prefix “di”, “tri” or “tetra” is being used with the location of the carbon on which it is present.
Rule 5- If more than one substituent is present, and they are different. So, these will be named in alphabetical order.
- Considering the above mentioned rules, we can easily say that the IUPAC name of the given compound is Tetraammineaquachlorocobalt(III)sulphate.

Therefore, the answer is option (A).

Note:
The IUPAC is needed because earlier every chemist gave its own new name to the molecule it discovered, making it difficult to study them. It has laid down some rules which govern the naming of all the organic compounds. This is necessary so that there is uniform nomenclature to be followed world-wide.