Chapter 22, Problem 7STP

Interpretation Introduction

Interpretation:

The correct name for the compound needs to be determined.

Concept introduction:

The organic compounds generally contain carbon atoms. The naming of organic compounds is done by considering three main terms which are prefix, suffix and the root name. The longest chain in the compound is first identified and named that will be the root name for the compound. For example, if there are 3 carbon atoms in the longest chain, the root name will be “prop”. To determine the suffix, functional group should be identified. For example, alcohol group will have suffix −ol, aldehyde will have suffix −al. If there is no functional group the suffix will be −ane. In the last step, side groups are identified and named. Prefix is used to give number of side groups and substituent’s present on the main carbon chain.

Answer to Problem 7STP

2, 3-difluorobutane.

Explanation of Solution

Reason for correct options:

The given compound is as follows:

The numbering is done in the above compound as follows:

Here, methyl group is present at 3^rd position. The main carbon chain contains 6 carbon atoms.

Thus, the name of the organic compound will be 3-methyl hexane.

Thus, the correct option is (a).

Conclusion

Reason for incorrect options:

2-ethyl pentane is incorrect because the numbering of C atoms should takes place such that main carbon chain contains maximum number of carbon atoms. Thus, the main chain will have 6 carbon atoms not 5.

Similarly, 2-propyl butane and 1-ethyl-1-methyl butane are incorrect because according to them main carbon chain will have 4 carbon atoms.

Therefore, options (b), (c) and (d) are incorrect.