Unit2 Flashcards
How are alcohols produced
Fermentation
What is fermentation
Enzymes convert carbohydrates (glucose) into ethanol and carbon dioxide
To meet the market production, ethanol is made by…
The catalysed hydration of ethene
What makes a Primary alcohol
Two hydrogen atoms bonded to the carbon atom, bonded to the oh hydroxyl functional group
(Exception is methanol )
A primary alcohol is equivalent to…
One alkane with one of its end hydrogens replaced by an hydroxyl functional group
Methanol and ethanol do not have…
Isomers that are alcohols
In a secondary alcohol…
Only one hydrogen atom is bonded to the carbon atom bonded to the hydroxyl functional group
Define a tertiary alcohol
The carbon atom bonded to the hydroxyl functional group has no hydrogen bonded to it
Carboxylic acids contain the functional group…
CooH
Carboxylic acids are formed
in the two stage mild oxidation of primary alcohols
Primary ➡️aldehyde➡️carboxylic acid
Ox Ox
Methanoic acid
Formic acid
HcooH
Ethanoic acid
Vinegar
CH3CooH
Propanoic acid
Ch3Ch2COOH
General formula for carboxylic acids
CnH2n-1COOH
Hydrochloric, nitric, and sulfuric acids are all strong acids as they
completely disparate into their ions
HCl➡️H*+Cl-
Carboxylic acids are weak acids as they
Only partially dislocate into their ions
Carboxylic Acids react in a similar way as strong acids with the four bases which are…
MAZIT metals
Metal Oxides
Metal Carbides
Alkalies (metal hydroxides)
Propanoic acid reacts with sodium hydroxide to form….
Sodium propionate
A salt
Name a salt of carboxylic acids thar are used as preservatives in the food industry
Calcium phosphate stops growth of mold
Alcohol +carboxylic acid 🔁??!
Ester +water
All esters contain an ester link, what is this?
O
⏸
➖C➖O➖
OR
➖COO
Describe esterification
(Making esters)
The carboxylic acid functional group condenses with the alcohol functional group to produce an ester link plus water
During esterification concentrated sulphuric acid is used to supply…
H+ ions
Concentrated sulfuric acid increases the…
Easter yeild by removing water…
According to le chatliers…
Esterification of ethanol with propanoic acid produces…
Ethyl propanoate
The first part of an esters name is from the …
Alcohol used
The second part of an esters name is from the …
Carboxylic acid
When making an easter why do we use a water bath
Alcohol and ester are flammable (Alternitive to bunsen burner)
When making an easter why do we use concentrated sulfuric acid
Provide H*(aq) ions
When making an ester why do we use a wet paper towel
Acts as a condenser
Stops alcohol and ester evaporating away
How do we know we have an ester
An immansible layer of ester
Distinctive smell
What is the purpose of NaHCO3 (aq) solution
To neutralise acid and any exess carboxylic acid
Esters prepared from alcohols and carboxylic acids with the same no. Of carbons have the same molecular mass and are therefore…
Isomers
Name some uses of esters
Flavouring
Perfumes
Adhesives
Medical applications
Hydrolysation of an ester produces…
The original alcohol and carboxylic acid
Hydrolysis
the break down pf large molecules into smaller molecules by the addition of water
Hydrolysing an ester using an acid
Requires the ester to be heated under reflux using dilute H* (aq) ions
What is the draw back of hydrolysing an ester using an acid?
The acid catalysed hydrolysis is reversible resulting in a mixture of alcohol/ carboxylic acid/ ester and water
Hydrolysis of an ester can be achieved by hydrolysing an ester using
a strong alkali.
To achieve complete hydrolysis of an ester the ester has to be added to..
A strong alkali and heated under reflux for approximately 30 minutes
Why is limonene insoluble in water
Its non polar so Its a hydrocarbon
Why is furanol soluble in water
All its functional groups are polar so it is soluble
Why is vanillin soluble in water
All its functional groups are polar
Why is eugenol insoluble
As an aromatic ring and a hydrocarbon chain exert a greater effect on solubility
Despite the polar functional groups
Properties of capsaicin
Insoluble in cold water
Responsible for the hot chili taste of jalapeños
Drinking water doesn’t take away the hot chilli effect but drinking milk does
Why is asparagus cooked in oil or butter
The flavour molecules in asparagus are water soluble so steaming or boiling it is not recommended as flavour would b lost
Why is broccoli boiled
The flavour molecules are soluble in oil so should be steamed or boiled to retain flavour
Vitamins
Can be water or oil soluble.
Fruits and veg containing vitamin C loose vitamin C when cooked in water
What is an example of oxidation
Burning alcohols in oxygen
Alcohols can undergo milder oxidation where the products depend on
Whether the alcohol is primary, secondary or Tertiary