Question

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.

Answer 1

Answer: The given substances are placed in order from most soluble in water to least soluble in water as follows.

         $MgCl_{2}$ > $C_{4}H_{9}OH$ > $C_{3}H_{8}$ > $CH_{4}$

Explanation:

It is known that like dissolves like which means a polar compound will be soluble in a polar solvent. And, a non-polar compound will be soluble in non-polar solvent.

Ionic compounds are soluble in polar solvent like water. For example, $MgCl_{2}$ is an ionic compound and it is readily soluble in water.

2-butanol ($C_{4}H_{9}OH$) is also a polar compound and it will also dissolve in water but to a lesser extent as compared to magnesium chloride.

Whereas both methane and propane are non-polar in nature. But as propane is larger in size as compared to methane so, it will be slightly more soluble in water as compared to methane.

Thus, we can conclude that the given substances are placed in order from most soluble in water to least soluble in water as follows.

     $MgCl_{2}$ > $C_{4}H_{9}OH$ > $C_{3}H_{8}$ > $CH_{4}$