Module 7 Reactions

Question 1

Alkene: Hydration Reaction

Answer 1

Alkene + H20 —> Alcohol

Catalyst: Dilute H2SO4

Question 2

Alcohol: Dehydration Reaction

Answer 2

Alchol –> Alkene + H20

Catalyst: Concentration H2SO4

Question 3

Alkane: Subsitution Reaction

Answer 3

Alkane + X2 (e.g. Br2) —-> Haloalkane + HX

Catalyst: UV Light

Question 4

Alkene: Hydrogenation Reaction

Answer 4

Alkene + H2 —> Alkane

Catalyst: Metal Catalyst e.g. Ni

Question 5

Haloalkane: Substitution Reaction

Answer 5

Haloalkane + OH- (e.g. NaOH, or any strong base) —> Alcohol + Salt (e.g. NaBr)
- No catalyst

Question 6

Alcohol: Substitution Reaction

Answer 6

Alcohol + HX (e.g. HCL) —> Haloalkane + H20
- No Catalyst

Doesn’t have to be an Alcohol, can be a hydroxyl group.

e.g. Carboxylic Acid (OH Group on the end) + NH3 —-> Amide + H20

CH3CH2CO OH + H NH2 —> CH3CH2CONH2 + H20
(OH + H = H20 and NH2 replaces the OH group to make Amide)

Question 7

Alkene: Addition Reaction(s)

Answer 7

Alkene + X2 —> Haloalkane
Alkene + HX —> Haloalkane (Markovnikov Rule)
- No Catalyst

Question 8

Fermentation Reaction

Answer 8

Glucose —> Ethanol + CO2

Catalyst: Yeast

Question 9

Primary Alcohol: Oxidation Reaction

Answer 9

2 Part Reaction:
Primary Alchohol + KMnO4(Potasium Permangenante) or K2Cr2O7(Potasium Dichromate) —> Aldehyde —-> Carboxylic Acid
Catalyst: Dilute H2SO4

Question 10

Secondary Alcohol: Oxidation Reaction

Answer 10

Secondary Alcohol + KMnO4(Potasium Permangenante) or K2Cr2O7(Potasium Dichromate) —> Ketone
Catalyst: Dilute H2SO4

Question 11

Esterfication Reaction

Answer 11

Carboxylic Acid + Alcohol —> Ester (oate) + H2O
Catalyst: Concentrated H2SO4

• Reflux needed: Condensor used to keep volatile reactant and product inside of mixture
• H2SO4 Added drop by drop to prevent large heat generation (Exothermic when added)
• Anti bumping granuals to ensure boiling smoothly.

Question 12

What test is used for the presence of Alkenes?

Answer 12

Bromine Water Test: (Alkene Addition Reaction)

• Bromine water goes colourless in the prescense of alkenes
• Alkenes react spontaneously with bromine water due to their unsaturated nature. … ◦Therefore, when alkenes come into contact with bromine water, they cause it to decolorize.

Question 13

What test is used for the presence of esters?

Answer 13

• Smell Test, different Esters produce a distrinct smell.

- Pour mixture into some water, most esters are insoluable and form a thin layer on the surface.

Question 14

What test is used to distinguish between primary and secondary alcohol oxidation products?

Answer 14

Tollens Test (Silver Mirror)

• Used to distinguish between and aldehyde and ketones
• Tollens Reagent (Silver Nitrate and Amonia) oxidies aldehydes but not ketones as aldehyes are readily oxidised.
• The silver ions are reduced to metallic silver when aldehydes are oxidised, which forms a layer called silver mirror

Question 15

What test is used to distinguish between primary, secondary and teriary alcohols?

Answer 15

Lucas Test

• Lucas Reagent (ZnCl2 and HCl)
• Based on the difference in reactivity of the 3 classes of alcohols within hydrogen halides
• Tertiary Alcohols react immediately with reagent, turning solution turbid
• Secondary Alcohols react within 5 minutes
• Primary Alcohols do not react at room temp.

Question 16

What are Double bonds made of?

Answer 16

• Made up of both a sigma and pi bond

- Makes it more reactive than a single bond

Question 17

What is a single bond made of?

Answer 17

• one sigma bond