reaction pathways - unit 4 AOS 1

Question 1

addition reactions

Answer 1

• alkenes
• akene to alkane
• alkene to dihaloalkane
• alkene to primary haloalkane
• alkene to primary alcohol
• alkene monomer to polymer

Question 2

substitution reactions

Answer 2

• alkane and primary haloalkanes
• alkane to primary haloalkane
• primary haloalkane to primary alcohol
• primary alcohol to primary amine

Question 3

oxidation reactions

Question 4

esterification

Answer 4

• primary alcohol and carboxylic acid to ester and water

Question 5

hydrolysis

Answer 5

• ester and water to primary alcohol and carboxylic acid

Question 6

transesterification

Question 7

alkene to alkane

Answer 7

• addition (hydrogenation)
• alkene + hydrogen gas → alkene
• conditions: heat and Ni(s)

Question 8

alkene to dihaloalkane

Answer 8

• addition (halogenation)
• alkene + halogen gas → dihaloalkane
• conditions: halogen gas

Question 9

alkene to primary haloalkane

Answer 9

• addition
• alkene + hydrogen halide → primary haloalkane

Question 10

alkene to primary alcohol

Answer 10

• addition
• alkene + steam → primary alcohol
• conditions: presence of stream and H3PO4

Question 11

alkene monomer to polymer

Answer 11

• addition (polymerisation)
• [akene + alkene]n → [alkene-alkene]n

Question 12

alkane to primary haloalkane

Answer 12

• substitution
• alkane + halogen gas → primary haloalkane + hydrogen halide
• poly substitution
• conditions: UV light or heat

Question 13

primary haloalkane to primary alcohol

Answer 13

• substitution
• can be done with either H20 or NaOH
• primary haloalkane + H20 → primary alcohol + hydrogen halide (very slow)
• primary haloalkane + NaOH → primary alcohol + sodium halide

Question 14

primary alcohol to primary amine

Answer 14

• substitution
• primary alcohol + NH3 → primary amine + water
• conditions: NH3/alumina/heat

Question 15

esterification

Answer 15

• condensation
• turns a primary alcohol and a carboxylic acid into ester and water
• carboxylic acid + alcohol → ester and water
• OH from carboxylic acid and H from alcohol
• conditions: H2SO4 (l)/heat

Question 16

hydrolysis

Answer 16

• turns an ester and water into a carboxylic acid and a primary alcohol
• aster + water → primary alcohol + water
• conditions: H+(aq) and heat

Question 17

hydrolysis and condensation of proteins

Answer 17

• Proteins can be chemically digested in a process known as hydrolysis, breaking the bonds that hold its ‘building blocks’ (amino acids) together. it requires enzymes.
• Proteins (also called polypeptides) are the products of condensation reactions occurring in the body between 2-amino acids. A polypeptide is formed from a condensation reaction between multiple (more than two) amino acids. The COOH groups react with the NH2 groups to form multiple amide or peptide links (CONH).

Question 18

condensation and hydrolysis of carbohydrates

Answer 18

• Carbohydrates, a major component of the food we eat, are broken down in the body through the process of hydrolysis. This process involves the addition of water and the presence of enzymes to convert carbohydrates into a form the human body can use for energy: monosaccharides
• The primary building blocks of starch (a type of carbohydrate) are simple ‘ring sugars’ known as monosaccharides
• Using these three simple monosaccharide rings as our basic structural units, we can increase the complexity of carbohydrates by linking two of them together by an ether link (−COC−). This ether linkage is also referred to as a glycosidic linkage, and is specific to the oxygen ‘bridge’ that forms between two ring sugars

Question 19

condensation and hydrolysis of lipids

Answer 19

• Triglycerides (fats) are broken down by the process of hydrolysis in the presence of enzymes, so that the body can obtain energy from the food we eat
• The fatty acids that are produced are then oxidised to produce carbon dioxide and water
• Triglycerides are fats (solid) or oils (liquid) formed in plants when three long chain fatty acids react with glycerol. Glycerol helps create the backbone of the triglyceride molecule linking the three fatty acids

Question 20

transesterification to make diesel

Answer 20

triglyceride + alcohol → methyl esters (biodiesel) + glycerol

OH-(aq) catalyst

Question 21

percentage yield

Answer 21

actual/theoretical x 100

• calculate the theoretical using stoichiometry

Question 22

atom economy

Answer 22

molar mass of desired product/molar mass of all reactants

Question 23

advantages of high atom economy

Answer 23

• conserve natural resources
• environmental protection and less waste products that impact the environment
• less hazardous waste
• cost efficiency

Question 24

primary haloalkane to primary amine

Answer 24

two step process

primary haloalkane → Alkylammonium halide salt → Primary amine + ammonium halide

conditions: 2NH3(aq)/ethanol/heat