Categories, properties and reactions of organic compounds

Question 1

Boiling point: increase in carbon chain length

Answer 1

-increase in boiling point due to the increase in strength of dispersion forces between the molecules

Question 2

Boiling point: functional groups

Answer 2

• compounds that contain functional groups have higher boiling points to alkanes of similar molar mass.
• due to presence of H-bonding

Question 3

Viscosity

Answer 3

-the more dispersion forces, the higher the viscosity. therefore increase in chain length or presence of functional groups= increase in viscosity.

Question 4

Flash point definition

Answer 4

the lowest temperature at which a substance can vapourise to form a mixture that will ignite in air.

Question 5

flash point

Answer 5

• as intermolecular bonding increases, the boiling and flash points will also increase.

Question 6

addition reaction

Answer 6

-multiple bonds must be present

Question 7

addition reaction (alcohol)

Answer 7

alkene + 300C + H2SO4(l) = alcohol

Question 8

substitution reaction

Answer 8

• at least 2 new proucts are formed

- catalyst in the form of UV light (easy to control) or heat

Question 9

oxidation of alcohols

Answer 9

• change in oxidation numbers

- ^^ increase in number of C-O bonds and a simultaneous decrease in the number of C-H bonds

Question 10

Oxidation of alcohols examples

Answer 10

Primary: alcohol + Cr2O7- + H+ (to make it an acidified environment) = aldehyde –> + H+ + Cr2072- = carboxylic acid.
secondary: alcohol + Cr2O72- + H+ = ketone (or aldehyde??? no carboxylic tho as the OH is not terminally located)

Question 11

esterification all

Answer 11

• a type of condensation reaction = water released

- alcohol + carboxylic acid + H2SO4(l)

Question 12

hydrolysis all

Answer 12

• water is used to break an ester link.

- ester= alcohol + carboxylic acid

Question 13

condensation all

Answer 13

• releases water
• carboxylic acid + amine = amide
• ammonia + carboxylic acid = amide

Question 14

combustion

Answer 14

you should know this by now

Question 15

ways to get primary alcohol

Answer 15

• alkane (uv light and halogen), haloalkynes (KOH), alcohol
• alkene (H2SO4(l)), alcohol
• alkene, haloalkane (KOH), alcohol

Question 16

ways to get primary amines

Answer 16

• alkane (UV light and halogen), haloalkane (NH3), amnie (+H2O)
• ^^ haloalkane (KOH), alcohol (NH3, 400C, alumina), amine (+h2o)
• alchol (NH3, 400C, alumina), amine (+h2o).
• alkene, haloalkane, etc
• carboxylic acid, amine

Question 17

ways to get carboxylic acid

Answer 17

-alcohol (primary) + H+ + Cr2O72- = carboxylic acid

Question 18

changes in Cr2O72-

Answer 18

Cr2O7-2 (yellow) –> Cr3+ (green)

Question 19

changes in MnO4-

Answer 19

MnO4- (purple) –> Mn+2 (colourless)