Describe the physical properties of alkenes.

(N/A) Physical properties: Alkenes resemble alkanes in their physical properties,except for differences in isomerism and polarity.
Physical state: The first three members are gases,the next fourteen are liquids,and higher members are solids. $Ethene$ is a colourless gas with a faint sweet smell. All other alkenes are colourless and odourless,insoluble in water,but fairly soluble in nonpolar solvents like benzene and petroleum ether.
Boiling point: Boiling point increases with an increase in molecular size and weight. Adding a $-CH_{2}-$ group increases the boiling point by $20-30 \ K$.
General trends: Boiling and melting points of alkenes are generally higher than those of corresponding alkanes. Straight-chain isomers have higher boiling points than branched isomers. The boiling point of the $trans$ isomer is typically higher than that of the $cis$ isomer,while the melting point of the $trans$ isomer is often lower than that of the $cis$ isomer.

$IUPAC$ Name and Structure	$B.P. \ (K)$ and $M.P. \ (K)$
$Ethene$: $CH_{2}=CH_{2}$	$B.P.: 104 \ K, M.P.: 171 \ K$
$Prop-1-ene$: $CH_{2}=CH-CH_{3}$	$B.P.: 225 \ K, M.P.: 108 \ K$
$But-1-ene$: $CH_{2}=CH-CH_{2}-CH_{3}$	$B.P.: 266.5 \ K, M.P.: 88 \ K$
$Pent-1-ene$: $CH_{2}=CH(CH_{2})_{2}-CH_{3}$	$B.P.: 303 \ K, M.P.: 108 \ K$
$Hex-1-ene$: $CH_{2}=CH(CH_{2})_{3}-CH_{3}$	$B.P.: 336.5 \ K, M.P.: 135 \ K$
$Hept-1-ene$: $CH_{2}=CH(CH_{2})_{4}-CH_{3}$	$B.P.: 366.0 \ K, M.P.: 154 \ K$
$Oct-1-ene$: $CH_{2}=CH(CH_{2})_{5}-CH_{3}$	$B.P.: 395.5 \ K, M.P.: 169 \ K$
$2-Methylbut-2-ene$: $CH_{3}-CH=C(CH_{3})_{2}$	$B.P.: 312.0 \ K, M.P.: 150 \ K$
$2,3\text{-Dimethylbut-2-ene}: (CH_3)_2C=C(CH_3)_2$	B.P.: $346 \text{ K}$, M.P.: $199 \text{ K}$