AP Chemistry Unit 2 Video Quizzes

When one atom transfers one or more valence electrons to another atom a(n) _____________ bond is formed.

ionic

Which of the following bonds are polar?

C–Se 

C–O

Cl–Cl

O=O

N–H

C–H

C–O and N–H

Rank the bonds formed between O–C, Cl–Ca, N–S, and O–Si in order of increasing ionic character.

N–S < O–C < O–Si < Cl–Ca

Why does MgCl₂ (2326 kJ/mol) have a stronger lattice energy than LiCl (834 kJ/mol)?

The Mg ion has a 2+ charge which is twice the charge of the lithium ion, causing the attraction with the chlorine ion to be stronger.

What is the main factor contributing to the difference in lattice energies in the lithium halogen compounds on the table?

Bond	Lattice Energy (KJ/mol)
LiF	1030
LiCl	834
LiI	730

The size of the halogen ion

Which bond has the highest bond energy?

N - - - N

Why do solid ionic compounds form crystal lattice structures?

To maximize attractive forces and minimize repulsive forces between ions

Use the properties shown in the table to explain why KF has a larger density than KCl.

	KCl (s)	Kf (s)
Ion Charges	K+Cl-	K+F-
Molar Mass (g/mol)	74.55	58.01
Density (g/cm3)	1.98	2.48
Internuclear Distance (nm)	0.267	0.217

F has a smaller atomic radius so the internuclear distance of KF is smaller which means more K⁺F^- ions can be packed into a cubic centimeter.

 Which of the following arrangements does a basic cubic crystal lattice follow?

 

ABABAB

The ability of a material to deform, usually by stretching along its length. This property allows us to make wires.

ductility

In rose gold, some of the gold atoms are replaced by copper to make the metal stronger. This is an example of a(n):

Substitutional alloy

 Solids have many different properties. _________ solids are known for their ability to be flattened into a sheet, stretched into a wire, and to conduct electricity well.

metallic

Which of the following is the correct lewis structure for nitrate, NO₃^-1

Which of the following molecules has three bonding pairs and one lone pair of electrons around the central atom?

i) HCN

ii) NH₄⁺

iii) H₃O⁺

iv) BH₃

v) NH₃

vi) CO₂

iii and v

Which of the following has two bonding pairs and two lone pairs of electrons around the central atom?

H₂S

Which of the following does NOT represent an exception to the octet rule?

NO2-

Which element follows the duet rule?

He

Which of the following is the most likely lewis structure for phosphate, PO₄^3- ?

Which atom is most likely to have the odd electron in NO₂?

Nitrogen because it is less electronegative and it will have a formal charge of +1

What is the formal charge on each atom in the N₂O Lewis structure below, read from left to right?

0, +1, -1

What is the carbon-oxygen bond order in the carbonate ion, CO₃^2- ?

1.5

1

1

Which molecule has resonance structures?

SO2

What is the electron geometry of hydrogen sulfide, H₂S?

Tetrahedral

What is the molecular geometry of phosphine, PH₃?

Trigonal Pyramidal

Use the Lewis structure below to explain why CF₄ is non-polar.

The tetrahedral molecular shape of CF₄ allows the dipoles to cancel

What is the hybridization of Br in BrF₃?

sp3d

Aspirin has _____ central atoms with sp² hybridization and a trigonal planar geometry.

8

For ICl₄^- identify the hybridization of the I atom and the geometric shape of the molecule.

sp3d2; square planar

What is the hybridization and bond angle of the carbon atom in oxalic acid?

sp3; 120