Organic Chemistry QUIZ 1

Chapter 1

Every atom except for H, He, and B wants to have ____________ total valence electrons.

Add lone pairs until the atom has enough electrons to be stable!

eight

Every atom except for H, He, and B wants to have eight total valence electrons.

Add _______________ until the atom has enough electrons to be stable!

lone pairs

Formal charge

Valence Electrons (for the neutral atom)

8 — (2X # of Bonds)

Non-bonded valence electrons

#of bonds to atom

Ionic

Polar covalent

Nonpolar covalent

>1.7

1.7-0.5

<0.5

0

Tetrahedral

109.5

1

Trigonal pyramidal

<109.5

2

Bent

<109.5

0

Trigonal planar

120

1

Bent

<120

0

Linear

180

______________ bonds: Made of 1 sigma bond and 0 pi bonds.

Single

_____________ bonds: Made of 1 sigma bond and 1 pi bond.

Double

______________ bonds: Made of 1 sigma bond and 2 pi bonds. [1, 2, 3]

Triple

sp³

sp²

sp

4

3

2

All ___________ bonds = hybrid orbitals or s-orbitals kissing

sigma

All sigma bonds = ______________ orbitals or s-orbitals kissing

hybrid

All ____________ bonds = p-orbitals waving hello

pi

More intermolecular forces = ________________ boiling point

higher

London dispersion

Dipole-dipole

Hydrogen bonding

A molecule has a ____________ if it contains polar bonds that do not cancel each other out in 3D space

dipole

Bonds that are ____________________ are weaker

longer

Bonds that are __________ are stronger

shorter

The # of bonds & polarity of bonds ___________ the length and strength

affect

More bonds = ___________ than less bonds

stronger

More polar = __________ bond

stronger

If there are several polar molecules, you can determine which is most polar by considering which has the greatest ________________ difference

electronegativity

Ionic

Polar covalent

Hydrogen bond donor

Nonpolar covalent

2 nonmetals share 2 electrons =

Covalent bond

Pi and sigma bonds are types of _____________ bonds

covalent

______ bonds are head-on

Sigma

________ bonds include s, p, or hybrids along the internuclear axis

Sigma

Sigma bonds are _______ than pi bonds

stronger

___________ bonds are sideways

Pi

_________ bonds include unhybridized p & are perpendicular to the internuclear axis

Pi

Polar =_________

hydrophilic

Nonpolar = __________

Hydrophobic

Larger atomic radius = _______________

longer

For neutral atoms, follow the _________ rule = outer shell = 8 valence electrons!

Ex.) Oxygen is in group 16, so it has 6 valence electrons.

So, 8-6 = 2.

So, it is divalent.

Octet

If the electronegativity difference is:

• __________: metal + nonmetal
  ΔEN = ≥2
  
  

• Polar: unequal/asymmetrical
  ΔEN = 0.5-1.9
  
  

• Nonpolar: equal/symmetrical
  ΔEN =< 0.5

Ionic

If the electronegativity difference is:

• Ionic: metal + nonmetal
  ΔEN = ≥2
  
  

• __________: unequal/asymmetrical
  ΔEN = 0.5-1.9
  
  

• Nonpolar: equal/symmetrical
  ΔEN =< 0.5

Polar

If the electronegativity difference is:

• Ionic: metal + nonmetal
  ΔEN = ≥2
  
  

• Polar: unequal/asymmetrical
  ΔEN = 0.5-1.9
  
  

• ___________: equal/symmetrical
  ΔEN =< 0.5

Nonpolar

In _______________ bonds, metal transfers electrons to the nonmetal

ionic

s

p

sp

sp²

sp³

Hydrogen bond _____________:

• Hydrogen bond covalently bonded to a strongly electronegative atom such as N, O, F

• Usually written as D—H, where D would be the _______ of the atom

donor

Hydrogen bond ______________:

• Consists of an electronegative atom that possesses a lone pair of electrons

• Common examples include lone pairs on N, O, F

acceptor

Intermolecular Forces ordered from ______________ strong:

Ion > H > D-D > London

most to least

Stronger IMF’s = ____________ boiling point

higher

Molecules that result from constructive interference— lower energy & holds bonding electrons

Bonding molecules

Molecules that result from destructive interference— higher energy & contains a node

Antibonding molecules

Highest Occupied Molecular Orbital

HOMO

Lowest Unoccupied Molecular Orbital

• Receives incoming electrons during reactions

LUMO

Electrons fill orbitals in order of increasing energy, starting with the lowest energy orbital first

1s → 2s → 2p

Aufbau principle

Each orbital can hold a maximum of two electrons, and they must have opposite spins.

Pauli Exclusion principle

When filling degenerate orbitals, one electron is placed in each orbital singly before pairing up.

Hund’s rule

Orbitals that reside at the exact same energy level

Ex.) 2p, 2p_x, 2p_y, 2p_z

Degenerate orbitals

A point or plane where the wavefunction Ψ = 0 , meaning the electron density (Ψ²) is zero

Node