Unbranched alkanes melting points

Consequently, for unbranched alkanes, melting and boiling points increase with chain length. 

Alkanes with long, unbranched chains tend to have higher melting points, boiling points, and enthalpies of vaporization than those of their branched isomers. The difference arises because, compared with unbranched molecules, the atoms of neighboring branched molecules cannot get as close together (Fig. 18.5). As a result, molecules with branched chains have weaker intermolecular forces than their unbranched isomers. 

FIGURE 18.4 The melting and boiling points of the unbranched alkanes from CH4 to C]()H, 4. 

Why do branched-chain alkanes have lower melting points and boiling points than unbranched alkanes with the same number of carbon atoms ... 

Unbranched alkanes tend to have higher melting points, boiling points, and heats of vaporization than their branched structural isomers. 

FIGURE 4.3 (a) Boiling points of unbranched alkanes (in red) and cycloaltenes (in white), (b) Melting points of unbranched alkanes. 

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