14.1 -14.2 Flashcards
What function group do alcohols have
-OH (hydroxyl)
What is the general formula for alcohols
- CnH2n+1OH
What are the three type of alcohols
1) Primary alcohol
2) secondary alcohol
3) Tertiary alcohol
What is a primary alchol
- when the OH is bonded to a C that is bonded to one other carbon
What is a secondary alcohol
- when the OH is bonded to a C that is bonded to two other carbon
What is a tertiary alcohol
- when the OH is bonded to a C that is bonded to three other carbon
Describe the solubility of alcohols
- alcohols are polar so they interact with water molecules via hydrogen bonds and can dissolves in water
- as the delta negative oxygen is attracted to the delta positive hydrogen
What happens to the solubility as the carbon chain in alcohol increases
- longer carbon chains are insoluble because the carbon chain is non-polar and it reduces the interaction water can make with the alcohol
Why do alcohols have a higher boiling point than molecules of a similar relative mass
- as they have hydrogen bonding which is the strongest type of intermolecular force making alcohol less volatile
What does the term volatility refer to
- the tendency of a substance to vaporise
How do alcohols makes haloalkanes
- substitution reaction (halide takes the place of OH)
Reagent: sodium halide
Catalyst: H2SO4
What happens in a dehydration of alcohol reaction, and what do you form
- eliminate water from an alcohol
- produce an alkene
What is the reagent and catalyst for dehydration of alcohols
Reagent: heat
Catalyst: acid catalyst ( H2SO4 or H3PO4)
What can dehydration of non-primary alcohols lead to
- 3 different alkenes ( always check for E/Z isomerism)
What are alcohols used for
- to generate energy as they are a fuel
How do alcohols burns
- readily with a blue light
What are the products of combustion of alcohols
- carbon dioxide and water
In combustion of alcohols what is happening to the alcohol
- it is being oxidised
What mild oxidising agent can alcohols be oxidised using
- potassium dichromate
What type of alcohol is oxidised to make ketones
- secondary alcohols
What type of alcohols are oxidised to make aldehydes then carboxylic acids
- primary alcohols
What is the reagent and catalyst when reacting primary alcohols to form aldehydes then carboxylic acid
Reagent: K2Cr2O7
Catalyst: H2SO4
What is the reagent and catalyst when reacting secondary alcohols to form ketones
Reagent: K2Cr2O7
Catalyst: H2SO4
What is the only way we can oxides tertiary alcohols
- by burning them
What experimental technique do we use when oxidising primary alcohols to aldehydes then ketones
- distillation and reflux
- distillation to obtain the aldehyde
- then add more K2Cr2O7 and reflux to turn the aldehyde to a carboxylic acid
How do we oxidise a secondary alcohol to form a ketone
- using redox and oxidising agent (K2Cr2O7)
