Tell whether the following pairs of compounds are identical, constitutional isomers, stereoisomers, or unrelated. (a) cis-1,3-Dibromocyclohexane and trans-1,4-dibromocyclohexane (b) 2,3-Dimethylhexane and 2,3,3-trimethylpentane

     (a) Constitutional Isomers

     (b) Constitutional Isomers

Explanation:

Constitutional isomers are also known with the name Structural Isomers. These are the compounds which have same chemical formula but differ in arrangement of atoms i.e. structure.

Both the compounds cis-1,3-dibromocyclohexane and trans-1,4-dibromocyclohexane have the same chemical formula but have different structure as shown in the image below.

In the second case the compounds 2,3-dimethylhexane and 2,3,3-trimethylpentane, both have same chemical formula but have different structures which is shown in the image below.

Thus it is clear that in both the groups (a) and (b) the given compounds are Constitutional Isomers.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.