IM forces and lab techniques

Question 1

What are the three intra-molecular forces?

Answer 1

Covalent. Ionic (have least diff between EN). Metallic Bonds. FORCES WITHIN a molecule.

Question 2

What are the four intermolecular forces?

Answer 2

1. Ion-dipole: ionic compounds interacting with polar cmpds
2. Hydrogen Bonding : H-NOF
3. Dipole-dipole
4. London Dispersion

Question 3

tollens test (Ag2O /NH3 or Ag(NH3)2+)

Answer 3

ALDEHYDES (sides of flask are coated with silver mirror)

Question 4

Iodoform (I2/OH)

Answer 4

METHYL KETONES

yellow precipitate forms (CHI3)

Question 5

Silver Nitrate in Alcohol (AgNo3 in alcohol)

Answer 5

Alkyl Halides

precipitate of Ag compound formed

Question 6

Bromine test (Br1/CCl4)

Answer 6

ALKENES AND ALKYNES

brown color of bromine disappears

Question 7

Baeyer Test (dilute KMnO4)

Answer 7

AlKENES AND ALKYNES

purple solution turns to brown precip

Question 8

Jones Test (CrO3/H2SO4)

Answer 8

1º and 2º alcohols

orange reagent turns blue-green

Question 9

Lucas test (ZnCl2 / HCl)

Answer 9

2º and 3º and benzylic alcohols

cloudy sol’n initially, then separate layer forms

Question 10

The stronger a molecules intermolecular forces ====

Answer 10

• the higher its boiling point
• the higher its melting point
• the lower the vapor pressure

Question 11

How do you extract carboxylic acids?

Answer 11

with aq NaOH and NaHCO3

Question 12

How do you extract phenols?

Answer 12

w aq NaOH

Question 13

How do you extract amines?

Answer 13

w aq HCl

Question 14

What do you use distillation for?

Answer 14

• separates mixtures of two or more VOLATILE liquids with LARGE BP differences by BOILING

Question 15

Fractional Distillation

Answer 15

Used when two VOLATILE liquids have boiling points that are close together

• by boiling

Question 16

Recrystallization

Answer 16

Dissolves an impure compound in a hot solvent and gradually precipitates the pure compound as the solution cools down.

Question 17

Sublimation

Answer 17

• purifies VOLATILE solids by converting to gas

Question 18

Gas-liquid chromatography

Answer 18

Used to determine the relative abundance of each compound in a liquid mixture

• separate volatile substances for ANALYSIS
• separates by boiling point
• lowest boiling point comes off the fastest

Question 19

Thin Layer Chromatography

Answer 19

separates compounds by their solubility in the solvent (polarity).

most soluble compounds travel the fastest and furthest up the plate

-usually uses a polar plate and non polar solvent
-cmpd that tavels furthest is most nonpolar
Rf is a number we use to tell how far up the TLC plate a cmpd travels

Rf= A/B

B is the solvent line

Question 20

Metallic Properties

Answer 20

variable hardness and melting point

conductive

Question 21

Ionic Properties

Answer 21

high melting point
brittle
hard

Question 22

Network Properties

Answer 22

high melting point
hard
non-conductive

Question 23

Molecular Properties

Answer 23

low melting point

non-conductive