alcohols 4E Flashcards
what is the functional groups of alcohols?
-OH
what is -OH connected to and how?
it is covalently bonded to a carbon chain
what is the formula of ethanol?
C2H5OH
(CH3CH2OH)
what is the molecular formula of methanol?
CH4O
what is the molecular formula of ethanol?
C2H6O
what is the molecular formula of propan-1-ol?
C3H8O
what is the molecular formula of butan-1-ol?
C4H10O
what is the structural formula for methanol?
CH3OH
what is the structural formula for ethanol?
CH3CH2OH
what is the structural formula for propan-1-ol?
CH3CH2CH2OH
what is the structural formula for butan-1-ol?
CH3CH2CH2CH2OH
draw out the displayed formula for the first 4 alcohols. what are their names?
check p.288 for reference
methanol, ethanol, propan-1-ol, butan-1-ol
what does each part of the word methanol tell you?
meth - number of carbon atoms
an - molecules are saturated (NO DOUBLE CARBON BONDS)
ol - there is an -OH functional group
what does the 1 in propan-1-ol tell you?
it tells you where the -OH group is in the carbon chain
what are propan-1-ol and propan-2-ol?
structural isomers
what happens when alcohols burn?
they from carbon dioxide and water
what is the equation for ethanol burning?
C2H5OH(l) + 3O2(g) -> 2CO2(g) + 3H3O(l)
what is ethanol?
it is a bioful
what is a biofuel?
a fuel that is made from biological sources, such as sugar cane or corn
what happens when an alcohol is left in air?
it is oxidised by the air in the presence of microbes (microbial oxidation)
what happens to ethanol when it is left in air?
it is oxidised by the help of microorganisms such as bacteria or yeast to form ethanoic acid
what is the formula for ethanoic acid?
CH3COOH
name a way in which ethanol can be oxidised? (in a lab)
it can be oxidised by heating with potassium dichromate (VI) in dilute sulfuric acid.
1. the oxidising agent is a mixture of potassium dichromate (VI) and dilute sulfuric acid. it is a strong oxidising agent with the formula K2Cr2O7. the sulfuric acid is important for the potassium dichromate (VI) to act as an oxidising agent
2. a few drops of ethanol are added to a solution containing the orange mixture of potassium dichromate (VI) and dilute H2SO4 in a test tube.
3. heat the tube in A HOT WATER BATH
4. the solution turns green and now contains a very dilute solution of ethanoic acid together with other products.
5. the green colour 9indicated the precense of Cr3+ ions, which are formed when potassium dichromate (VI) is reduced.
the product also smells like vinegar (an acid)
what do you need to do to stay safe when oxidising ethanol in a lab?
- wear eye protection
- add the reaction very slowly to prevent too violent a reaction
- do not point the mouth of the test tube towards you as the contents may spit out