Organic Chemistry Chapter 1-3

Lewis Structures, Resonance, VSPER and Acid-Base Rxns

A wedge represents what in a bond-line structure?

A group coming out of the page (towards the reader)

A dash represents what in a bond-line structure?

A group going into the page (away from the reader)

A characteristic group of atoms/bonds that show predictable behaviour

A functional group

How many bonds will a carbon atom have it bears either a positive or negative charge?

Three

What tool is used to show the flow of protons (electrons) in drawing resonance structures?

Curved arrows

What should you always avoid doing when working with curved arrows?

Avoid breaking a single bond and never exceed an octet

The most important rule of identifying significance of a resonance structure?

The most significant resonance form has the greatest number of filled octets

The second most important rule of identifying significance of a resonance structure?

The structure with the fewer formal charges is more significant than one with more

The third most important rule of identifying significance of a resonance structure?

If everything else is equal, a structure with a negative charge on the more electronegative element will be more significant

The fourth most important rule of identifying significance of a resonance structure?

If everything else (lewis structures included) are equally good, then they will contribute equally to resonance

What type of lone pair occupies a p orbital and participates in resonance

Delocalized

What type of lone pair does not participate in resonance

A localized lone pair

What does a molecular formula do?

lists kind and number of each type of atom in a molecule, no bonding pattern

What does a structural formula do?

shows each atom and bond in a
molecule

What does a condensed formula do?

shows all the atoms in a molecule in sequential order indicating which atoms are bonded to which

What does a line formula do?

assume a carbon atom at any location
where lines intersect

A carbanion has how many bonds, how many lone pairs and what charge?

3 H bonds, 1 lone pair and a negative charge

What is a carbocation?

A positively charged Carbon with three bonds and one empty orbital that can stabilize positive charge through resonance or inductive effects.

When an oxygen has a negative charge it has…

1 bond and 3 lone pairs

When an oxygen has a positive charge it has…

3 bonds and 1 lone pair

When an oxygen has a no charge it has…

2 bonds and 2 lone pairs.

Curved arrows cannot originate from what?

An element, they can only come from bonds or lone pairs.

Which is more stable, delocalized or localized lone pairs?

Delocalized lone pairs

What is the general rule about localized lone pairs?

hen an atom possesses a pi (double) bond and a lone pair, they both will not participate in
resonance

What are constitutional isomers?

Isomers that share the same molecular formula but have different connectivity of atoms and different physical properties.

Second row elements obey what rule?

The octet rule, bonding to achieve noble gas electron configuration.

When does a formal charge occur?

when atoms do not exhibit the appropriate number of valence electrons.

What does VSEPR stand for?

valence shell electron pair repulsion

The physical properties of a compound are determined by what?

Intermolecular forces

A type of attractive interaction which occurs when a lone pair of an electronegative atom interacts with an electron poor hydrogen atom (EX: O or N)

Hydrogen Bonding

What are london dispersion forces?

Forces that result from the interaction between transient __dipole moments and are stronger for larger molecules due to their larger surface area and ability to accommodate more interactions

What is the valence shell?

The outermost electron shell of an atom

What are valence electrons?

Electrons in the valence shell of an atom. These electrons are used in forming chemical bonds

An atom that gains an electron became an

Anion

An atom that loses an electron

Cation

What is an ionic bond?

A chemical bond resulting from the electrostatic attraction of an anion and a cation.

What is a covalent bond?

A chemical bond resulting from two atoms sharing one or more pairs of electrons

Hydrogens can only make

1 bond

Carbon can make how many bonds

4 bonds with no lone pairs

Nitrogen can make how many bonds

3 bonds and 1 lone pair

Oxygen can make how many bonds

2 bonds and 2 lone pairs

Halogen can make how many bonds

1 bond and 3 lone pair

A Bronsted-Lowry Acid is a proton

Donor

A Bronsted-Lowry Base is a proton

Acceptor

A Lewis acid is a proton

Acceptor

A Lewis base is a proton

Donor

The mechanism of proton transfer always includes how many curved arrows?

2

A strong acid has what type of pKa

low pKa

A weak acid has what type of pKa

high pKa

The equilibrium of an acid-base reaction always favors the side with

the weaker acid and base

When multiple factors compete, this principle explains the order of general priority

ARIO

The stronger the acid, what happens to the base

the weaker the conjugate base

A weak acid has what kind of Ka value?

low Ka

A strong acid has what kind of Ka

high Ka

What is the equation to find pKa?

-log(Ka)

What is the equation for finding Ka

10^(-pKa)

What does ARIO stand for?

Atom, Resonance, Inductive Effect, Ortibal

What does “sp3” mean in terms of bonds?

There are four sigma (single) bonds

What does “sp2” mean in terms of bonds?

3 sigma (single) bonds, 1 pi (double) bond

What does “sp” mean in terms of bonds?

2 sigma (single) bonds, 2 pi (double) bonds.

A double bond counts as..

1 sigma (single) bonds and 1 pi (double) bond

A triple bond counts as..

1 sigma (single) bonds and 2 pi (double) bond

The stronger the acid, the base sees an ____ in stability

Increase

How do we determine the stability of a conjugate base?

we look at the stability of the lone pair.