AP Chemistry | Unit 2 Day Quizzes

The diagram above shows two resonance structures for a molecule of C6H6. The phenomenon shown in the diagram best supports which of the following claims about the bonding in C6H6 ?

A) In the C6H6C6H6 molecule, all the bonds between the carbon atoms have the same length.

Which of the following statements, if true, would support the claim that the NO3− ion, represented above, has three resonance structures?

A) The NO3− ion is not a polar species.

The particle-level diagram above represents the structure of solid KF. Although the molar mass of KCl is greater than that of KF, the density of KCl is actually less than that of KF. Which of the following representations of the structure of KCl best helps to explain this phenomenon?

A) [Diagram shows alternating positive and negative ions; the negative ions are larger than the positive ions]

Which of the following diagrams best illustrates how a displacement in an ionic crystal results in cleavage and brittleness?

A) [Diagram shows half of the atoms shifted downwards; positive ions are next to positive ions and negative ions are next to negative ions]

Which of the following diagrams best depicts an alloy of Ni and B?

A) [Diagram shows large white circles with smaller gray circles in-between the large white circles]

The elements C and Se have the same electronegativity value, 2.55. Which of the following claims about the compound that forms from C and Se is most likely to be true?

B) The carbon-to-selenium bond is nonpolar covalent.

Which of the following Lewis diagrams best represents the bonding in the N2O molecule, considering formal charges?

B) [Diagram shows a triple bond between the two nitrogen atoms and a single bond from one nitrogen to the oxygen atom]

Steel is an alloy containing Fe atoms and C atoms. Which of the following diagrams best represents the particle-level structure of steel?

B) [Diagram shows large, white circles representing Fe atoms and small, gray circles representing C atoms in the gaps of the Fe atoms]

Copper atoms and zinc atoms have the same atomic radius, 135 picometers. Based on this information, which of the following diagrams best represents an alloy containing only copper and zinc atoms?

B) [Diagram shows many white circles with a few gray circles, representing atoms; both circles are the same size]

In the following diagrams, elements are represented by X and Z, which form molecular compounds with one another. Which diagram represents a molecule that has a bent molecular geometry?

B) [Diagram shows the central atom (X) with two pairs of unbonded electrons]

To make Au stronger and harder, it is often alloyed with other metals, such as Cu and Ag. Consider two alloys, one of Au and Cu and one of Au and Ag, each with the same mole fraction of Au. If the Au/Cu alloy is harder than the Au/Ag alloy, then which of the following is the best explanation based on the information in the table above?

C) Cu atoms are smaller than Ag atoms, thus they interfere more with the displacement of atoms in the alloy.

Two pure elements react to form a compound. One element is an alkali metal, X, and the other element is a halogen, Z. Which of the following is the most valid scientific claim that can be made about the compound?

C) It contains ionic bonds.

Which of the following correctly indicates whether the solid represented by the particulate model shown above conducts electricity and explains why or why not?

C) It does not conduct electricity because its ions cannot move freely within the solid.

Of the following single bonds, which is the LEAST polar?

C) O—F

A particle-level diagram of a metallic element is shown above. Typically, metals are both malleable and ductile. The best explanation for these properties is that the electrons involved in bonding among metal atoms are

C) equally shared and form nondirectional bonds

Which of the following scientific claims about the bond in the molecular compound HF is most likely to be true?

D) The bond is highly polar.

The energy required to dissociate an ionic solid into gaseous ions (lattice energy) for the compounds NaF and MgF2 is shown in the table above. On the basis of Coulomb's law, which of the following best helps to explain the large difference between the lattice energies of NaF and MgF2 ?

D) The charge of the Mg cation is larger than that of the Na cation.

Lewis diagrams of molecules of three different hydrocarbons are shown above. Which of the following claims about the molecules is best supported by the diagrams?

D) The strongest carbon-to-carbon bond occurs in molecule 3.

Of the following compounds, which is the most ionic?

E) CaCl2

Which of the following compounds contains both ionic and covalent bonds?

E) NH4Cl