"1. Potassium chloride and methane"1. Potassium chloride and methane, a volatile hydrocarbon, and an ionic solid. NOT MUTUALLY SOLUBLE.
"2. Potassium chloride and carbon tetrachloride"2. Potassium chloride and carbon tetrachloride, another (less) volatile hydrocarbon, and an ionic solid. NO.
"3. Potassium chloride and water"3. Potassium chloride and water, an ionic solid, and a strongly polar solvent. YES.
"4. Methane and carbon tetrachloride"4. Methane and carbon tetrachloride, a non-polar volatile organic halide, and another volatile hydrocarbon. PROBABLY.
"5. Methane and water"5. Methane and water, a non-polar volatile hydrocarbon, and water. NO. (Given water's properties as a solvent, there would be some minimal solubility of the gas in the water.)