Question

Are alkanes soluble in water?

Answer 1

Alkanes are highly saturated hydrocarbons consisting of only carbon and hydrogen atoms. There is not much difference in electronegativities between carbon and hydrogen. Thus, alkanes are not polar, as non-polar compounds can be able to dissolve in non-polar solvents only. Whereas water is a polar solvent.

Complete answer:
Hydrocarbons are the compounds consisting of only carbon and hydrogen atoms. Alkanes, alkenes and alkynes are the important hydrocarbons. Alkanes are the saturated hydrocarbons in which the carbon and hydrogen are involved in a single bond. The general molecular formula of alkanes is ${C_n}{H_{2n + 2}}$ , where n is the number of carbon atoms.
Carbon has the value of electronegativity of $2.55$ and hydrogen has the value of electronegativity of $2.2$ . Thus, there is not much difference of electronegativity between these two atoms which leads to the non-polarity or no movement of electrons.
Due to the non-polarity of electrons, alkanes were considered as non-polar compounds.
Polar compounds dissolve in polar solvents like water or ethanol. Whereas non-polar compounds will dissolve in non-polar solvents like kerosene or benzene.
Water is a polar compound and is not able to dissolve alkanes in it. Thus, alkanes were not soluble in water.

Note:
Water is a polar solvent, any compound that is capable of breakage of oxygen-hydrogen bonds in water can only be able to dissolve in water, as the oxygen-hydrogen bonds were very strong. The non-polar compounds like alkanes were not able to break any bonds in oxygen and did not involve hydrogen bonding with water.