Which compound is more soluble in the given solvent, and WHY?

a)
Methanol (CH₃OH) is more soluble in water than methane (CH₄). This is because the -OH groups in methanol can form intermolecular hydrogen bonds with water, and this will stabilize the solution of methanol in water.

b)
Chloroform (CHCl₃) is more soluble in water than carbon tetrachloride. Chloroform consists of polar molecules, while carbon tetrachloride consists of non-polar molecules. When a polar solvent like water is used, polar molecules are more soluble than non-polar molecules. Hence, chloroform is more soluble.