Question Video: Identifying the Correct Relationships between Polar and Nonpolar Solvents and Solutes | Nagwa Question Video: Identifying the Correct Relationships between Polar and Nonpolar Solvents and Solutes | Nagwa

Question Video: Identifying the Correct Relationships between Polar and Nonpolar Solvents and Solutes Chemistry • First Year of Secondary School

Which of the following statements about solvents is correct? [A] Polar solvents dissolve polar and nonpolar solutes, and nonpolar solvents dissolve nonpolar solutes. [B] Polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes. [C] Polar solvents dissolve nonpolar solutes, and nonpolar solvents dissolve polar and nonpolar solutes. [D] Nonpolar solvents dissolve polar solutes, and polar solvents dissolve polar and nonpolar solutes. [E] Nonpolar solvents dissolve polar solutes, and polar solvents dissolve polar solutes.

03:49

Video Transcript

Which of the following statements about solvents is correct? (A) Polar solvents dissolve polar and nonpolar solutes, and nonpolar solvents dissolve nonpolar solutes. (B) Polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes. (C) Polar solvents dissolve nonpolar solutes, and nonpolar solvents dissolve polar and nonpolar solutes. (D) Nonpolar solvents dissolve polar solutes, and polar solvents dissolve polar and nonpolar solutes. Or (E) nonpolar solvents dissolve polar solutes, and polar solvents dissolve polar solutes.

This question asks us to correctly define some of the relationships between polar and nonpolar solvents and solutes. A solute is a substance that dissolves into another substance to form a solution. The substance which the solute dissolves into to form the solution is known as the solvent.

One of the ways in which we can classify solvents depends on their polarity. Polar solvents consist of polar molecules. A polar molecule is a molecule that contains polar bonds, which cause the molecule as a whole to have an asymmetric distribution of electron density. These polar bonds are caused by differences in electronegativity between the atoms in the molecule. Molecules with a symmetrical distribution of electron density are referred to as nonpolar.

Generally speaking, it is only possible to dissolve solutes in a solvent if the interactions between the solvent and solute are similar to the interactions which already exist between the solute particles themselves and the solvent particles themselves. We can summarize this idea with the phrase “like dissolves like.”

Polar molecules, such as hydrogen fluoride, have opposite partial charges, which allow for electrostatic interactions to occur between molecules. In this example of hydrogen fluoride, the intermolecular interactions are especially strong due to hydrogen bonding, which is a special type of dipole–dipole interaction. These electrostatic interactions are much stronger than the dispersion forces which exist between nonpolar molecules, such as molecular hydrogen.

Due to the constant movement of electrons, a molecule can develop a temporary dipole that induces a dipole in another molecule if they are close enough. This results in attractive forces between nonpolar molecules, which are instantaneous, induced dipole moments.

Polar molecules do not mix with nonpolar substances because the interactions between polar molecules are significantly stronger than the interactions which could be formed between polar and nonpolar molecules. This means that mixing together the two substances would be energetically unfavorable. And only substances of similar polarities can dissolve in one another.

Let’s have a look at our answer choices. We can see that answer choice (B) applies this “like dissolves like” idea, which states that polar solvents can dissolve polar solutes and nonpolar solvents can dissolve nonpolar solutes.

So which of the following statements about solvents is correct? The correct answer is (B). Polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes.

Join Nagwa Classes

Attend live sessions on Nagwa Classes to boost your learning with guidance and advice from an expert teacher!

  • Interactive Sessions
  • Chat & Messaging
  • Realistic Exam Questions

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy