chapter 11 - properties + reactions of organic compounds

Question 1

boiling point

Answer 1

temperature that a substance changes state from liquid to gas

Question 2

solubility

Answer 2

maximum amount of a substance that will dissolve ina given volume

Question 3

boiling points of non-polar compounds

Answer 3

alkanes, alkenes, alynes, symmetrical haloalkanes
- dispersion forces
- increase as no. electrons increase
- straight chain have higher bpt than branched due to ability to come close to one another

Question 4

solubility of non-polar compounds

Answer 4

• immiscible (dont dissolve in water)
• only weak dispersion forces are possible between water molecules and non- polar molecule
• not stronger than hydrogen bonds
• hydrogen bonds wont break and reform with organic compound

Question 5

boiling points of polar compounds

Answer 5

haloalkanes, ketones, aldehydes, esters
- dipole- dipole attraction + dispersion forces
- d-d increases with polarity
- bpt increases with intermolecular forces

Question 6

solubility of polar compounds

Answer 6

• d-d allows small degree of solubility of haloalkanes
• small aldehydes and ketone are soluble
• carbonyl groups enables some hydrogen donds

Question 7

boiling points of polar compounds with hydrogen bonding

Answer 7

alcohols, carboxylic acids, amines, amides
- hydrogen bonding
- bpt increases
- carboxylic acid is very high

Question 8

solubility of polar compounds and hydrogen bonding

Answer 8

• hydrogen bonds in water will break and reform with organic compound
• very soluble

Question 9

viscosity

Answer 9

the resistance of a liquid to pouring
- increases as intermolecular forces increase

Question 10

flashpoint

Answer 10

the lowest temperature at which a liquid forms sufficient vapour to ignite when an ignition source is applied
- increases as intermolecular forces increase and it relies on liquid becoming a vapour

Question 11

combustion reactions

Answer 11

redox reactions between fuel and oxygen
- produce water and carbon dioxide

Question 12

substitution reactions - alkanes

Answer 12

alkane + halogen = (uv light) haloalkane + hydrogen halide

Question 13

substitution reaction - haloalkanes

Answer 13

formation of alcohol
haloalkane + hydroxide ions (NaOH) = alcohol + dihalide
haloalkane + water = (catalyst) alcohol + hydrogen halide
formation of amines
haloalkane + ammonia = amine + hydrogen halide

Question 14

addition reactions

Answer 14

• reaction with halogen
  alkene + halogen = dihaloalkane
• reaction with hydrogen
  alkene + hydrogen = (catalyst) alkane
• reaction with hydrogen halide
  alkene + hydrogen halide = haloalkane
• reaction with water
  alkene + H2O (g) = (H3PO4) alcohol
• addition polymerisation
  alkene + alkene = polyalkene

Question 15

oxidation of alcohols

Answer 15

1. alcohol oxidised to form aldehyde (H+ is oxidising agent)
2. if heated under reflux, oxidation continues to produce carboxylic acid
   primary alcohol = (H+/Cr2O72-) aldehyde = (H+/Cr2O72-/ heat) carboxylic acid
   secondary alcohol = (H+/ Cr2O72-) ketone

Question 16

making esters

Answer 16

alcohol + carboxylic acid = (H+/ H2SO4) ester + water
condensation reaction

Question 17

making amides

Answer 17

amine + carboxylic acid = amide + water

Question 18

hydrolysis of esters

Answer 18

reverse condensation
ester + water = (catalyst/ heat) carboxylic acid + alcohol

Question 19

percentage yield

Answer 19

1. convert mass to mol of reactant
2. use stoichiometry to find mol of product
3. find mass of products
4. use equation to find % yield