All experiments for organics Term 3 Flashcards
Describe the experiment for oxidation of Alcohols Reaction
In this reaction ethanol, butan-1-ol, butan-2-ol and methyl propan-2-ol were oxidised with (limited) acidified potassium permanganate
Why is limited KMnO4- required in oxidation of alcohols
limited was required because otherwise the permanganate would be in excess and therefore would not be able to see the colour change.
Describe the oxidation of ethanol and it’s speed
-primary alcohol meaning the carbon the functional group is attached to is only attached to one other carbon
-it has the most ‘spare’ bonds (between the carbon and hydrogen) which can break to form a double bond between the carbon and oxygen
-therefore it is oxidised the fastest.
Describe the oxidation of Butan-1-ol and it’s speed
-primary alcohol meaning the carbon the functional group is attached to is only attached to one other carbon
-it has the most ‘spare’ bonds (between the carbon and hydrogen) which can break to form a double bond between the carbon and oxygen, therefore it is oxidised the fastest.
Describe the oxidation of Butan-2-ol and it’s speed
-secondary alcohol meaning the carbon that the functional group is attached to is attached to two other carbons
-there is one ‘spare’ bond available, which can break to lose the hydrogen and form a double bond between the oxygen and the carbon.
-second fastest as it has less ‘spare’ bonds available than the primary alcohols.
Describe the oxidation of 2-methylpropan-2-ol and it’s speed
-tertiary alcohol, this means the carbon that the functional group is attached to has no spare bonds available
-double bond between the oxygen and carbon cannot be formed.
-therefore no reaction
What occured in the reaction of alcohols with sodium
All of the alcohols were reacted with sodium metal to form sodium alkoxides and hydrogen gas. The alkoxides are white solids.
Describe observations of ethanol reaction with sodium
Bubbled vigorously
Describe observations of Butan-1-ol reaction with sodium
Bubbled vigorously
Describe observations of Butan-2-ol reaction with sodium
Moderate bubbles
Describe observations of 2-methylpropan-2-ol reaction with sodium
Mild bubbles
Describe the experiment for oxidation of ester reactions
different alcohols were reacted with different carboxylic acids in presence of concentrated sulfuric acid+heat. Resulting products were fragrant esters and water.
-Heat was required for the reaction to occur
-Sulfuric acid acts as a catalyst, meaning it provides alternate pathway w/ lower activation energy, increasing rate of reaction. Also acts as dehydrating agent, removing water which causes reaction to shift to the right.
-condensation reaction (esterification) which reacts a carboxylic acid with an alcohol to form an ester and water.
How are fats and oils made
How are soaps made
(be able to right the reaction equation)
-Fats and oils made by reaction bwn a glycerol and three fatty acids (condensation reaction)
-Soap can be made reacting an oil w/ strong base (sodium hydroxide) - reaction=saponification
-forms the soap molecules and a glycerol molecule
Describe the reaction of soap with oils/fatty acids in soft water
-fatty acid and sodium dissociate to form sodium ions and fatty acid ions
-fatty acid ions have non-polar end and polar head
-non-polar end is attracted to the oil (hydrophobic) and head is attracted to the water (hydrophilic), -if enough soap molecules have attached to oil, w/ agitation, soap molecules will pull oil from fabric.
Describe the reaction of soap with oils/fatty acids in hard water
Compare the reaction of detergent with hard water?
-hard water is water containing a high concentration of Mg2+ and Ca2+
-the soap ions will react with these ions to form an insoluble compound called scum.
-soap will only form lather if all calcium ions precipitated out
-Detergent ions react with the Ca and Mg ions to form a soluble compound therefore does not require more detergent to form a lather
-Both soaps and detergents form micelles in water
