The State Of An Alkane

The physical properties of alkane change regularly with the increase of the number of carbon atoms in the molecule.
At room temperature 25°, alkanes containing 1 to 4 carbon atoms are gases.
Alkanes containing 5 to 16 carbon atoms are liquids. However, alkanes containing 10 to 19 carbon atoms can be solid at normal temperatures.
The n-alkanes containing more than 18 carbon atoms are solid, but until the n-alkanes containing 60 carbon atoms (melting point 99℃), the melting point does not exceed 100℃. Alkanes are non-polar molecules, dipole moment (dipole moment) is zero, but the distribution of electric charge in the molecule is not very uniform, can produce instantaneous dipole moment in the movement, instantaneous dipole moment between the interaction force (dispersion force), in addition to the molecule there is a very weak induction force. The force between these molecules is one or two orders of magnitude smaller than the chemical bond, and the energy required to overcome these forces is also low, so the melting point and boiling point of general organic compounds rarely exceed 300 ° C.