Organic Chemistry - Reactions

Question 1

Combustion reactions

1. Reaction
2. Info about reaction

Answer 1

1. Alkane + oxygen = Carbon dioxide + water

2. Highly exothermic + sort chain alkanes burn easily

Question 2

Esterfication

1. Reaction
2. Conditions for reaction

Answer 2

1. Primary alcohol + Carboxylic acid (Sulphuric acid)= Ester + water
2. Sulphuric acid added as a catalyst

Question 3

Haloalkanes from Alkanes (Substitution)

1. Reaction
2. Info about reaction

Answer 3

1. Alkane + Halogen (Heat)= Haloalkane + HX
2. Occur in the presence of heat or light. Causes dissociation of halogen molecule into radicals which are unstable and bond easily

Question 4

Alcohol and Haloalkanes (Substitution)
HBr Or HCl with alcohols
1. Reaction
2. Conditions for reactions

Dilute bases with Haloalkanes

1. Reaction
2. Conditions for reaction

Answer 4

HBr or HCl with alcohols
1. Alcohol + HBr/HCl = Haloalkane + Water
2. • Tertiary alcohols at room temperature
• Primary and secondary react slow and need high temp

Bases/H2O with Haloalkanes(Hydrolysis)

1. Haloalkane + Dilute base (Ethanol)= Alcohol + Salt
2. Base is dissolved in ethanol, Haloalkane is added, then it is heated

Question 5

Hydrogenation (Addition)

1. Reaction
2. Conditions for reaction

Answer 5

H2 is added to an Alkene

1. Alkene + Hydrogen (Platinum)= Alkane
2. Alkene(non-polar) must be dissolved in a non-polar solvent with a catalyst such as Pt, Ni

Question 6

Halogenation (Addition)

1. Reaction
2. Conditions for reaction

Answer 6

Halogen is added to an alkene

1. Alkene + Cl2/Br2 = Haloalkane
2. Dissolve alkane in non-polar solvent, the reaction proceeds easily at room temperature

Question 7

Hydrohalogenation (Addition)

1. Reaction
2. Conditions for reaction

Answer 7

HCl/HBr/HI added to an Alkene

1. Alkene + HX = Haloalkane
2. Dissolve alkene in non-polar solvent and NO water must be present

Question 8

Hydration (Addition)

1. Reaction
2. Conditions for reaction

Answer 8

Water is added to an Alkene

1. Alkene + Water (50% H2SO4)= Alcohol
2. Must take place in dilute acid solution. Acid acts as catalyst. Must use strong dilute acid

Question 9

Markovnikov’s rule

Answer 9

When asymmetrical alkenes react with a HX, the H goes to the carbon with the most H’s and the x to the fewest

Question 10

Dehydrohalogenation (Elimination)

1. Reaction
2. Reaction conditions

Answer 10

Elimination of HX from Haloalkane

1. Haloalkane (Ethanol+NaOH/KOH)= Alkene + HX
2. 1. Haloalkane + KOH/NaOH (Ethanol)= Alkene + Salt + Water
3. Haloalkane and Concentrated NaOH/KOH dissolved in ethanol and heated.
   * reverse Markovnikov’s rule

Question 11

Cracking of alkanes

Answer 11

The chemical process in which longer chain hydrocarbon molecules are broken down into shorter more useful molecules

Question 12

Dehydration (Elimination)

1. Reaction
2. Conditions for reaction

Answer 12

Elimination of Water from an Alcohol

1. Alcohol (Conc. H2SO4)= Alkene + Water
2. Heating of alcohol with excess concentrated sulphuric acid