2-methyheptane will come in the first blank. In the second blank, 3-methylnonane and the third blank 3-ethyloctane.
The subject of the question is related to organic chemistry, which deals with the structures, properties, and reactions of organic compounds, primarily compounds containing carbon. The student is given a set of organic compounds with the task to complete pairs, draw structures for identified compounds, and to arrange given compounds in order of increasing boiling points.
For example, 3-ethyloctane would imply a straight-chain octane with an ethyl group (a two-carbon chain) attached to the third carbon of the main chain. Similarly, 2-methylheptane would have a methyl group (a one-carbon group) attached to the second carbon of the main heptane chain. Understanding how to name these organic molecules using IUPAC nomenclature is crucial in the field of organic chemistry.
Lastly, boiling points are generally affected by molecular weight, branching, and the presence of functional groups. For example, comparing ethyl methyl ether, isobutane (2-methylpropane), and acetone, the order of increasing boiling points would be influenced by factors such as molecular size, intermolecular forces, and the presence of polar functional groups.