Covalent Bonds and Molecular Structure

These flashcards cover key concepts and definitions related to covalent bonds, molecular structures, and acidity, based on lecture notes.

What is a covalent bond?

A covalent bond involves 2 atoms bonding through the sharing of electrons.

What determines the degree of electron sharing in covalent bonds?

Electronegativity determines the degree of sharing electrons in covalent bonds.

What are polar covalent bonds characterized by?

Polar covalent bonds have a significant difference in electronegativity (0.5 to 1.9), leading to uneven sharing of electrons.

What is the difference between polar and nonpolar covalent bonds?

Polar covalent bonds have dipoles due to uneven sharing, while nonpolar covalent bonds have little to no difference in electronegativity.

What is a sigma bond?

A sigma bond is formed by the end-to-end overlap of atomic orbitals.

What types of bonds do double and triple bonds consist of?

A double bond consists of one sigma bond and one pi bond, while a triple bond consists of one sigma bond and two pi bonds.

What is hybridization?

Hybridization refers to the mixing of atomic orbitals to form new hybrid orbitals suitable for pairing electrons.

What is the significance of bond angles in molecular geometry?

Bond angles help determine the shape of the molecule and provide insight into its hybridization and bonding.

What is a conjugate acid?

A conjugate acid is formed when a base gains a proton (H+), increasing its charge by one.

What is the relationship between pKa values and acidity?

Lower pKa values correspond to stronger acids, indicating that the equilibrium favors the side with more stable products.

What are heteroatoms?

Heteroatoms are atoms in a molecule that are not carbon or hydrogen.

What is the role of formal charges in molecular structures?

The net charge of a molecule is the sum of all formal charges, which helps determine the stability and reactivity of the molecule.

What are Lewis structures?

Lewis structures represent molecules, showing all valence electrons and bonds, while skeletal structures omit lone pairs.

How do electronegativity differences affect molecular polarity?

The greater the difference in electronegativity, the greater the dipole moment, contributing to a more polar bond.

What happens if carbon, nitrogen, or oxygen do not form the correct number of bonds?

If carbon does not form 4 bonds, it has a charge; if nitrogen does not form 3 bonds, it is charged; if oxygen does not form 2 bonds, it is charged.