AP Chemistry - Unit 8 MC

Front

What is the role of hydrogen bonding in the solubility of alcohols in water?

Back

Hydrogen bonding allows alcohols, like propanol, to interact with water molecules, increasing their solubility compared to nonpolar compounds like ethane.

Front

Which liquid substance has the weakest intermolecular forces among the following: CH3OH(l), C2H5OH(l), and H2O(l)?

Back

CH3OH(l) has the weakest intermolecular forces among the listed substances.

Front

What effect does decreasing the percentage of ethyl acetate in a solvent have on the distance traveled by products in thin-layer chromatography?

Back

Decreasing the percentage of ethyl acetate reduces the solvent's polarity, leading to less distance traveled by the products on the chromatogram.

Front

What properties indicate that a white crystalline solid is NaOH(s)?

Back

It melts at 320°C, does not conduct electricity as a solid, but conducts electricity in an aqueous solution.

Front

What does it indicate if the positive end of water molecules is pointed toward a particle in solution?

Back

It indicates that the particle is an anion, as the positive end of water molecules (hydrogen) is attracted to negatively charged particles.

Front

Define intermolecular forces and their significance in physical properties of substances.

Back

Intermolecular forces are the forces of attraction between molecules, significantly affecting boiling points, melting points, and solubility.

Front

What is the difference between polar and nonpolar molecules in terms of solubility in water?

Back

Polar molecules, which can form hydrogen bonds with water, are generally soluble in water, while nonpolar molecules are not.

Front

Explain the concept of thin-layer chromatography (TLC) and its purpose.

Back

TLC is a technique used to separate and identify compounds in a mixture based on their different affinities for a stationary phase and a mobile phase.

Front

What is the significance of a substance conducting electricity in an aqueous solution?

Back

It indicates that the substance dissociates into ions in water, allowing the solution to conduct electricity.

Front

How does the melting point of a substance relate to its intermolecular forces?

Back

A higher melting point typically indicates stronger intermolecular forces, as more energy is required to overcome these forces.