What Are the Physical Properties of Alkenes and Alkynes

Alkenes and alkynes are nonpolar compounds, and the only attractive forces between their molecules are dispersion forces (Section 3.8B). Therefore, their physical properties are similar to those of alkanes (Section 3.8) with the same carbon skeletons. Alkenes and alkynes that are liquid at room temperature have densities less than 1.0 g/mL. Thus, they are less dense than water. Like alkanes, alkenes and alkynes are nonpolar and are soluble in each other. Because of their contrasting polarity with water, they do not dissolve in water. Instead, they form two layers when mixed with water or another polar organic liquid such as ethanol. 

Tetramethylethylene and dimethylacetylene. Both a carbon-carbon double bond and a carbon-carbon triple bond are sites of high electron density and, therefore, sites of chemical reactivity. 

Describe what will happen when 1-nonene is added to the following compounds  

First determine the polarity of the solvent and the solute. Then apply the generalization, like dissolves like.  

1-Nonene is an alkene and, therefore, nonpolar. It will not dissolve in a polar solvent such as water. Water and 1-nonene will form two layers water, which has the higher density, will be the lower layer, and 1-nonene will be the upper layer. 

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