Lecture 1 - Bonding and Water

What is a covalent bond?

The sharing of valence electrons.

What is permanent dipole?

Covalent bond between two atoms with different electronegativities

Is water polar or non-polar?

Polar

What is a hydrogen bond?

Intermolecular attraction between a hydrogen atom covalently bonded to a highly electronegative atom (like Oxygen, Nitrogen, or Fluorine) and another nearby electronegative atom with a lone pair of electrons

What are the requirements for a hydrogen bond?

Hydrogen donor and acceptor.

What is a hydrogen donor?

Hydrogen bonded to an electronegative atom

What is a hydrogen acceptor?

A lone pair of electrons associated with an electronegative atom.

How many hydrogen bonds can each water molecule form?

Four

How many does a water molecule form on average?

Three

What are the van der Waals forces?

Dipole-dipole interactions (between charged atoms)

London dispersion forces (exist for every atom)

Is a hydrogen bond considered a dipole-dipole interaction?

Yes

What is hydrophobic effect?

The tendency of water molecules to minimize interactions with non-polar molecules in a solution, which causes non-polar compound to be forcefully associated with each other,

What is the benefit of hydrophobic effect?

A higher entropy (nature's tendency toward disorder, randomness, and energy dispersal). The clumped nature of the Nonpolar solvents decreases surface area therefore less hydrogen atoms have to surround the non-polar substances.

What is an amphipathic/amphiphilic molecule?

A molecule which experiences both hydrophilic interactions and hydrophobic effect

What is an example of an amphiphilic/amphipathic molecule?

Micelle