3. Bonding

Question 1

sigma bond vs pi bond

Answer 1

single bonds; allows free rotation around axis vs double and triple bonds; doesn’t allow free rotation around axis

Question 2

Know which bond is strongest b/w triple, double, single, sigma and pi bonds. Why is single bond stronger than sigma bond?

Answer 2

I pretty much laid out the order for you. S orbitals have more overlap than p orbitals

Question 3

Tetrahedron has what type of orbitals? What about alkenes? What about a triple bond or 2 adjacent double bonds?

Answer 3

sp3; sp2 120 degrees; sp 180 degrees

Question 4

Which elements do H bonds?

Answer 4

O, N, F; H bonds = strongest type of dipole dipole interaction

Question 5

What does increased branching do to bpt vs mpt?

Answer 5

Lowers it vs lowers it UNTIL BRANCHING BECOMES MORE SYMMETRICAL –> RAISES IT

Question 6

What is a conjugated system?

Answer 6

Alternating single bonds and multiple bonds; this allows pi e- to delocalized throughout unhybridized p orbitals OR heteroatoms with lone pairs of e-

Question 7

Molecular orbital vs bonding orbital vs antibonding orbital

Answer 7

When 2 atoms form a cmpd —> atomic orbitals interact => molecular orbital vs signs of 2 atomic orbitals that are same vs signs of 2 atomic orbitals that are different

Question 8

Principal vs azithumal/angular momentum vs magnetic vs spin quantum number

Answer 8

Energy level/shell, n, max # of e- w/in a shell: 2n^2 vs subshell, l, max # of e- w/in a subshell: 4l + 2, ranges from 0 to n-1 (ie. In the first shell, you have one subshell which is l=0; in the second shell, you have two subshells which are l=0 and l=1; etc); energy of subshells inc with increasing l values (ex: 3d has more energy than 4s) vs # of orbitals, ranges b/w l and -l including 0 vs spin and momentum, either +1/2 or -1/2

Question 9

S orbital vs p orbital vs node

Answer 9

Round and spherical, centered around nucleus vs 2 lobes located symmetrically around nucleus (like a dumbbell) vs area where probability of finding e- = zero (ie. At the nucleus)

Question 10

Hybrid orbital vs sp3 orbital vs sp2 orbital vs sp orbital

Answer 10

Formed by mixing diff types of orbitals vs 1 s orbital + 3 p orbitals = 4 sp3 orbitals, done by putting 1 2s e- into the last unoccupied p space, tetrahedral vs 1 s orbital + 2 p orbitals = 3 sp2 orbitals, alkenes, 120 degrees apart —> max repulsion vs 1 s orbital + p orbital = 2 sp orbitals, alkynes, 180 degrees apart —> linear

Question 11

Molecular orbitals contain how many max numbers of e-?

Answer 11

2 e- (remember: Pauli exclusion principle)

Question 12

Induction

Answer 12

Refers to distribution of charge across sigma bonds. Electronegative atoms like more e- around them —> more neg (this less electronegative atoms = more pos)

Question 13

Characteristics of aromatic cmpds

Answer 13

Nonpolar/Hydrophobic, inc acidity b/c they stabilize neg charges, cyclic, stable, planar, conjugated all around, Huckel’s rule: 4n+2 pi e- where n=any integer

Question 14

Hydrogenation of alkenes into alkanes involve what?

Answer 14

A metal catalyst