Question

When applied to a dish, soap makes grease soluble in water. Which explanation correctly supports the role of intermolecular forces in this common observation? The nonpolar end of a soap molecule attaches itself to grease. The nonpolar end of a soap molecule attaches itself to water. The polar soap molecule attaches itself to the dish. The polar soap molecule attaches itself to a nonpolar soap molecule.

Answer 1

Explanation:

Soaps attach to both water and grease molecules.

The grease molecules are attracted more strongly towards each other as compared to water molecules. Also, water molecules are smaller in size hence, strong intermolecular force is required to break the hydrogen bonds of water molecule so that grease or oil molecules can enter the water molecule.

A soap molecule goes in between water and grease molecule and helps them to bind. The force for linkage between water and grease molecule through the soap molecule is weak london dispersion force.

The soap molecule has its salt end as ionic and water soluble. When grease or oil is added to the soap and water solution then the soap acts as an emulsifier. The soap forms miscelles of the non-polar tails and grease molecules are trapped between these miscelles. This miscelle is easily soluble in water hence, the grease is washed away.

Thus, it can be concluded that the nonpolar end of a soap molecule attaches itself to grease.

Answer 2

Answer: The non-polar end of a soap molecule attaches itself to grease.

Explanation:

Soap molecule that is miscelle has two parts:

• Polar part or hydrophilic part : This part interacts with polar water molecules.
• Non-polar or hydrophobic : This part interacts with the non-polar molecules that is grease.

By the interaction of non-polar part with grease and interaction of  polar part with water due to which grease get easily dissolved in water.

Hence,the correct answer is : 'The non-polar end of a soap molecule attaches itself to grease'.