The reason that nonpolar oil will not dissolve in polar water is that the attractive forces between:
A. the oil molecules are ionic and the attractive forces between the water molecules are covalent.
B. the water molecules are weaker than the attractive forces between the water molecules and the oil molecules.
C. the oil molecules and the water molecules are weaker than those between the water molecules alone.
D. the oil molecules are weaker than the attractive forces between the water molecules and the oil molecules.
I don't think it is a but I don't know which one to choose
C is the correct answer. I just solved it myself.
I believe you are right about a.
I would choose C.
To determine the correct answer, let's break down the question:
The statement is that nonpolar oil will not dissolve in polar water. This suggests that there is a difference in the attractive forces between the oil molecules and the water molecules.
Option A suggests that the attractive forces between the oil molecules are ionic, while the attractive forces between water molecules are covalent. This is incorrect because both oil and water molecules are nonpolar, so they do not have ionic or covalent bonds.
Option B states that the water molecules are weaker than the attractive forces between water molecules and oil molecules. This is incorrect because water molecules have strong attractive forces due to hydrogen bonding.
Option C claims that the attractive forces between the oil molecules and the water molecules are weaker than the forces between water molecules alone. This is also incorrect because the question states that nonpolar oil will not dissolve in polar water, implying that the forces between oil molecules are stronger than the forces between oil and water molecules.
Option D suggests that the oil molecules are weaker than the attractive forces between water molecules and oil molecules. This is the correct answer. Nonpolar oil molecules do not have strong intermolecular forces like water molecules, so they cannot overcome the strong attraction between polar water molecules and mix with them.
Therefore, the correct answer is D.
To determine the correct answer, let's evaluate the properties and interactions between nonpolar oil and polar water.
Nonpolar substances are composed of molecules that have no permanent dipole moment, meaning the distribution of charge is even throughout the molecule. On the other hand, polar substances like water have an uneven distribution of charge, i.e., they have a dipole moment, with one end being slightly positive and the other end being slightly negative.
When a nonpolar oil is introduced to polar water, the polar water molecules form strong intermolecular forces called hydrogen bonds among themselves. These forces are formed due to the attraction between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another water molecule.
In contrast, the nonpolar oil molecules do not form hydrogen bonds because they do not have any polar groups that can interact with the water molecules. Instead, the oil molecules only have weak dispersion forces or London dispersion forces between them.
Now, let's go through the answer choices:
A. The oil molecules are nonpolar, so they cannot have ionic forces. Additionally, water molecules have a slight covalent character due to their polarity. So, this choice is incorrect.
B. The water molecules form strong hydrogen bonds with each other, which are relatively stronger than the interactions between water and oil molecules. Therefore, this choice is incorrect.
C. This choice suggests that both the oil-water interactions and water-water interactions are weaker than water-water interactions alone, which is not true. Therefore, this choice is incorrect.
D. The oil molecules have weaker forces of attraction with water molecules compared to the forces that exist between water molecules themselves. This is due to the nonpolar nature of oil and the absence of any polar groups to interact with water molecules. Therefore, this choice is correct.
Conclusion: The correct answer choice is D. The oil molecules are weaker than the attractive forces between the water molecules and the oil molecules.