Rank the following substances in order from most soluble in water to least soluble in water: methane, CH4; 2-butanol, C4H9OH; magnesium chloride, MgCl2; and propane, C3H8. Rank from most to least soluble in water. To rank items as equivalent, overlap them.

MgCl2 > C4H9OH > CH4 > C3H8.

Explanation:

Alkanes do not form hydrogen bonds and are insoluble in polar solvents e. g water. The hydrogen bonds between water molecules are move away from an alkane molecule and this worsens as their Carbon chain / molecular weight increases.

MgCl2 is soluble in water. Water essentially breaks down the ionic crystal lattice and the resulting solution is slightly basic.

Alcohols are generally soluble in water and this is because of the - OH group and its ability to form hydrogen bonds with water molecules. As applied to alkanes, as the carbon chain in the alkyl group increases, the solubility decreases.

From the most soluble to the least soluble,

MgCl2 > C4H9OH > CH4 > C3H8.