MP3: Three weeks test AP chemistry

Front

What is a Lewis structure?

Back

A Lewis structure is a diagram that shows the bonding between atoms of a molecule and the lone pairs of electrons that may exist. It helps in visualizing the arrangement of electrons.

Front

How do you determine the correct Lewis structure for a molecule?

Back

To determine the correct Lewis structure, count the total number of valence electrons, arrange the atoms, and distribute the electrons to satisfy the octet rule for each atom.

Front

What is the octet rule?

Back

The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons, achieving a stable electron configuration similar to that of noble gases.

Front

What is the molecular geometry of PBr3?

Back

The molecular geometry of PBr3 (phosphorus tribromide) is trigonal pyramidal due to the presence of a lone pair on the phosphorus atom.

Front

What is the molecular geometry of BF3?

Back

The molecular geometry of BF3 (boron trifluoride) is trigonal planar, as it has three bonding pairs and no lone pairs on the boron atom.

Front

What is the Lewis structure for water (H2O)?

Back

The Lewis structure for water shows the oxygen atom in the center with two hydrogen atoms bonded to it, and two lone pairs of electrons on the oxygen.

Front

What is the significance of double bonds in Lewis structures?

Back

Double bonds indicate that two pairs of electrons are shared between two atoms, which can affect the molecule's geometry and reactivity.

Front

How many double bonds are present in CCl4?

Back

CCl4 (carbon tetrachloride) has 0 double bonds; it has four single bonds between carbon and chlorine.

Front

What is the Lewis structure for CH2O?

Back

The Lewis structure for CH2O (formaldehyde) shows a carbon atom double bonded to an oxygen atom and single bonded to two hydrogen atoms.

Front

What is the role of lone pairs in Lewis structures?

Back

Lone pairs are pairs of valence electrons that are not involved in bonding. They can influence the shape and polarity of the molecule.