Unit 2.1: Introducing chemistry for biologists

What is an intramolecular bond?

Intramolecular bonds are bonds within molecules.

What is an intermolecular bond?

Intermolecular bonds are bonds between molecules.

What is an intramolecular bond?

Intramolecular bonds are bonds within molecules.

What is an intermolecular bond?

Intermolecular bonds are bonds between molecules.

What are the three types of intramolecular bonds?

Ionic Bonds

Covalent Bonds

Polar Covalent Bonds

What is an ionic bond?

An ionic bond forms when one atom transfers electrons to another atom. As a result, the atoms end up with a stable electron arrangement in their outer orbit, similar to that of a noble gas.

Ionic bonds occur with ____ and ____.

Metals and non-metals.

What is a covalent bond?

A chemical bond formed when two or more atoms share electrons.

Covalent bonds are formed between ____ and ____.

Non-metals and non-metals.

What is a polar covalent bond?

A covalent bond is an unequal sharing of valence electrons between atoms. One atom is pulling harder on the electrons than the other.

Types of intermolecular bonds are also collectively known as ____.

van der Waals forces.

What are the three types of intermolecular bonds?

London forces

Dipole-dipole forces

Hydrogen bond

Describe London forces

- Hold non-polar molecules together
- Very weak forces of attraction
- Momentary dipoles are created by the electrons contained within the compound, which are constantly in motion
- Weakest relative strength

Describe dipole-dipole forces

- Hold polar molecules together
- These forces are stronger than London forces

Describe hydrogen bonding

- Is formed between the electropositive hydrogen dipole and an electronegative dipole of oxygen, chlorine, or fluorine
- Strongest relative strength

electronegativity

hogging of electrons

hydrogen bonds

H-O, H-F, H-N

condensation

when two molecules COMBINE from removing H2O.

hydrolysis

“hydro” water “lysis” break down. Uses H2O to BREAK DOWN molecules.

hydrophobic

“phobic” resists water.

Hydrophilic

water loving.

Redox

Oxidation: process of LOSING electrons. Reduction: process of GAINING electrons.

neutralization

when an acid + base is used to produce= Water + salt.

pH scale

Acids 0-6, Neutral 7, Bases 8-14

Ionization

the process of breaking up molecules into ions +,-

acids

gain hydrogen ions + and create- hydronium

bases

bases lose ions - and create hydroxide “oxide”!!

strong acids and bases

ionize completely when in water

weak acids and bases

ionize partially when in water.

acid-base buffers

When a SMALL amount of acid/ base is added to neutralize the excess of acid and base. (conjugate is the one to neutralize)