Chem Exam 2

Question 1

Condensation Rxn/polymers

Answer 1

COOH links with OH or NH3 and lose H2O
diacid btw =O
diol/diamine btw -O/NH

Question 2

Examples of Condensation Polymers?

Answer 2

Amides, esters

Question 3

Addition polymers?

Answer 3

Hydrocarbon chain, ylene

Question 4

Steps of an oxidation

Answer 4

Primary alcohol -> aldehyde -> carboxylic acid

Question 5

Carboxylic Acid

Answer 5

-oic
Always C1
-C=OOH

Question 6

Esters

Answer 6

-oate
COOH + OH
C=OO
always C1

Question 7

Aldehydes

Answer 7

-al
Always C1
C=O-H

Question 8

Ketones

Answer 8

R-C=O-R

Question 9

Alcohols

Answer 9

R-OH

Question 10

Amines

Answer 10

Primary: NH2
Secondary: -NH-
Tertiary: three bonds to N

Question 11

Ethers

Answer 11

-polar

R-O-R

Question 12

Structural Isomers

Answer 12

Same Molecular Formula different connectivity

Question 13

Geometric Isomers

Answer 13

• cis/trans
• double bonds
• no chiral center
• different chemistry

Question 14

Enantiomers/Stereo Isomers

Answer 14

Chiral centers

-mirror images not super imposable

Question 15

What are examples of reducing agents?
What bonds form?
What functional group does the molecule go to?

Answer 15

Metal + Hydrogen : LiAlH4, NaBH4
= -> -
go to alcohol

Question 16

Examples of Oxidizing agents?
What bonds are made?
Order of oxidation?

Answer 16

Chromates/Dichromate
- -> =
primary alcohol-> aldehyde (or keytone) -> carbox acid

Question 17

When Sulfuric Acid is present what takes place?

Answer 17

Elimination

Double bonds form (creates unsaturation), H2O forms, lose OH

Question 18

Wen HI or HBr is present in a rxn what occurs?

Answer 18

Substitution

Lose OH, add I

Question 19

Substitution Rxn?

Answer 19

Replace H w/ Halogen

Question 20

Hydrogenation addition rxn

Answer 20

+H2
unsaturated -> saturated
=/= -> -

Question 21

Halogenation addition rxn

Answer 21

+X2

Question 22

Hydrohalogenation

Answer 22

+HX
Polar
=/triple bonds form and positive attacheds to C with most Hydrogens

Question 23

What happens to H and = in Oxidation?

Answer 23

Decrease H, add double bonds

Question 24

What happens to H in Reduction Rxn?

Answer 24

Increase H, lose =

Question 25

Addition to C=O

Answer 25

Polar added across C=O with positive to O

Question 26

Which hydrocarbons are Aliphatic? | What are their equations?

Answer 26

Alkenes/olefins: CnH2n | Alkynes CnH2n-2

Question 27

Aromatic and formula?

Answer 27

benzene ring | CnHn

Question 28

Chain Alkanes formula

Answer 28

CnH2n+2

Question 29

Formulas for iso and tert?

Answer 29

(CH3)2 | (CH3)3

Question 30

How do pi bonds relate to boiling point?

Answer 30

More pi bonds = more polar = higher boiling point

Question 31

Cis or trans more polar?

Answer 31

Cis>Trans

Question 32

If benzene is not a base, what is it called when naming?

Answer 32

"phenyl"

Question 33

Ester synthesis reaction?

Answer 33

acid + alcohol -> ester + H2O | C=O-OH + OH -> C=O-O + H2O

Question 34

Amide synthesis reaction?

Answer 34

weak base + strong acid-> ammonium salt NH2 + HCl -> NH3+ Cl- Carbox acid + ammonium salt -> amide + H2O C=O-OH + H-NHR' -> RCONHR' + H2O

Question 35

Examples and definition of condensation polymers?

Answer 35

Polyesters, polyamides | Remove small molecules (water)

Question 36

How many sigma/pi bonds in each type of bond?

Answer 36

Single: 1 sigma Double: 1 sigma 1 pi Triple: 1 sigma 2 pi

Question 37

Describe band gap in semiconductors, insulators, and conductors

Answer 37

Semiconductors: small band gap Insulators: large band gap Conductors: 0 band gap, metals

Question 38

n-type vs p-type doping? | What does doping do?

Answer 38

(n)egative type doping: electrons added, dopants have one extra val electron (p)ositive type doping: take away electrons; add holes; dopants have one less val electron Doping lowers the band gap and thus increases conductivity

Question 39

How does stability relate to bond order and bond length?

Answer 39

Most stable=Highest bond order=shortest length

Question 40

How do conductivity and temperature relate in semiconductors and conductors?

Answer 40

Semi: Cond increases as Temp increases Cond: Cond decreases as Temp increases

Question 41

Combustion Rxn?

Answer 41

Burn organic molecules in O2, creates CO2 and H2O

Question 42

All amino acids are chiral except? because?

Answer 42

Glycene because it is the simplest and has two H's | acid w/H + amine