Question

The IUPAC name of the compound $\left[ Cr{{\left( N{{H}_{3}} \right)}_{5}}NCS \right]\left[ ZnC{{l}_{4}} \right]$is:
A. pentaammine isothiocyanato-N-chromium (iii) tetrachlorido zincate (ii)
B. pentaammine isothiocyanato-N-chromate (iii) tetrachlorido zincate (ii)
C. pentaammine isothiocyanato-S-chromium (ii) tetrachlorido zincate (iii)
D. pentaammine isothiocyanato-S-chromium (iii) tetrachlorido zincate (ii)

Answer 1

Hint: In order to find out the IUPAC name of the compound we will first understand the process of writing IUPAC name of any compound and then we will write the IUPAC name of the given compound.

Complete answer:
We will first discuss about the rules to write the IUPAC name of any compound:
- We will identify the longest carbon chain present in the compound, which is called the parent chain. Then the next step is to identify all the substituent.
- Number the carbons of the parent chain from the last that gives the lowest numbers to the substituents.
- If the same substituent appears more than once, then it is found that for any point the position is given where the substituent occurs.
- If there are two or more than two substituents, then they are written in alphabetical order. Instead of these rules there are some other rules also.
- Now, we given compound is:
As we know that Cr is in+3 oxidation state, hence the name is written in the order of cationic complex followed by anionic complex. The IUPAC name of the compound $\left[ Cr{{\left( N{{H}_{3}} \right)}_{5}}NCS \right]\left[ ZnC{{l}_{4}} \right]$ is pentaammine isothiocyanato-S-chromium (iii) tetrachlorido zincate

Hence, we can conclude that the correct option is (d), that is pentaammine isothiocyanato-S-chromium (iii) tetrachlorido zincate (ii)

Note: - The IUPAC nomenclature is a system of naming organic compounds, as given by the International Union of Pure and Applied Chemistry.
- It is written in the Blue book. We have discussed some of the rules in the solution, one must remember these rules in order to name any compound.