AP Chemistry Unit 3.1

Which of the following is the strongest type of interaction that occurs between the atoms within the circled areas of the two molecules represented above? (Topic 3.1)

• Polar covalent bond

• Nonpolar covalent bond

• Hydrogen bond

• London dispersion forces

Based on the data in the table above, which of the following correctly predicts the relative strength of the attraction of Zn2+, Ca2+, and Ba2+ ions to water molecules in a solution, from strongest to weakest, and provides the correct reason? (Topic 3.1)

• Zn²⁺ > Ca²⁺ > Ba²⁺ because the smaller ions have a stronger coulombic attraction to water

• Zn²⁺ > Ca²⁺ > Ba²⁺ because the smaller ions are more electronegative

• Ba²⁺ > Ca²⁺ > Zn²⁺ because the larger ions are more polarizable

• Ba²⁺ > Ca²⁺ > Zn²⁺ because the larger ions are less electronegative

Tags

NGSS.HS-PS1-3

The figure above shows that in solid hydrogen fluoride there are two different distances between H atoms and F atoms. Which of the following best accounts for the two different distances? (Topic 3.2)

• Accommodation of the necessary bond angles in the formation of the solid

• Difference in strength between covalent bonds and intermolecular attractions

• Different isotopes of fluorine present in the samples

• Uneven repulsions among nonbonding electron pairs

Of the following, the best explanation for the fact that most gases are easily compressed is that the molecules in a gas (Topic 3.3)

• are in constant motion

• are relatively far apart

• have relatively small masses

• have a real, nonzero volume

• move slower as temperature decreases

Tags

NGSS.HS-PS3-2

The figure above represents three sealed 1.0 L vessels, each containing a different inert gas at 298 K. The pressure of Ar in the first vessel is 2.0 atm. The ratio of the numbers of Ar, Ne, and He atoms in the vessels is 2:1:6, respectively. After all the gases are combined in a previously evacuated 2.0 L vessel, what is the total pressure of the gases at 298 K? (Topic 3.4)

• 3.0 atm

• 4.5 atm

• 9.0 atm

• 18 atm