reactions of alkenes Flashcards
what occurs in a reaction of alkene
the double c-c bond breaks with each carbon in that bond forming a new bond to another element/molecule, each part of the other reactant forms a bond with each carbon in the double bond
what is an alcohol
contaions an -oh group known as a hydroxyl group, which replaces one hydrogen in the structure of an alkane
genmeral formula alcohols
CnH2n+1OH
what to remember when naming an alcohol
replace the suffix ‘an’ of the alkane with ‘ol’ and make sure the carbons are numbered from the end of the carbon chain that gives the lowest number to the OH group
solubility of alcohols
soluble in water as the OH gropup allows alcohol molecules to form hydrogen bonds with water molecules
polarity trend of alcohols
decreases as the molecule becomes larger because the length of the chain increases and more of the molecule is non-polar
boiling point of alcohols compared to hydrocarbons
have a much higher boiling point as the -oh group allows hydrogen bonding to occur between molecules and strengthens the intermolecular bonding, most alchols are liquid at room temp whereas hydrocarbons are gases
trend of boiling point in alcohols
increases as the size of the alcohol molecule increases due to an ioncrease in dispersion forces
how top name alcohols
name alkane as usual but then put a dash (-) the carbon number alcohol is bonded to (-) ‘ol’
combustion of alcohols
readily undergo combustion when reacting with oxygen to form CO2 and H2O
what are carboxylic acids
weak acids that are often present in food, giving it a sour taste, contain a carboxyl group (-COOH)
general formula carboxylic acid
CnH2n + 1 COOH
where are carboxylic acids found
some insect venoms, when food detiriorates,
how to name carboxylic acids
keep regular alkane name, then remove suffic “an” and replace with -oic acid
things to remeber when naming carboxylic acid
the carboxyl carbon can only occur on the end of the chain so is always carbon 1, the carbon is the carboxyl group is counted when naming the molecule
why are carboxylic acids acids
the elctrons are drawn away from the hydrogen atoms, allowing it to react with water to form H+ ions, so that the functional group can act as an acid
why to carboxylic acids have the highest boiling points
a dimer of two carboxylic acid monomers form two hydrogen bonds
what is an ester
often fragrent molecules that cosist of a carbonyl group (C double bonded to O) with a second oxygen bonded to the carbon atom to form -COO
general formula esters
R - COO - R’, where R and R’ are alkyl groups that may or may not be the same
how are esters formed
when carboxylic acids are heated with alohols in the presence of suphuric acid (catalyst)
what occurs during esterfication
the ester functional group is fortmed from the carboxyl functional group of the carbopxylic acid and the hydroxyl group of the alcohol, water is also produced
process of drawing ester reaction
- draw the structure of the reactants with the carboxyl group and Oh GROUP NEXT TPO EACH OTHER 2. identify the atoms in the reactants that will form the water bmolecule 3. draw the remaining structure of the ester
how to name esters
locate the functional group and carbonyl carbon 2. starting from the carbon in the functional group, determine the number of the carbons in the chain attached to it 3. name it according to the stem name, adding the suffic -oate (dervied from the carbopxylic acid) 4. the alkyl gropup bonded to the singly bonded oxygen atom is the front of the name (dervied from the alcohol)
boiling point of esters
lower boiling points than alcohols or carboxylic acids as they have no free hydroxyl groups so cannot form hydrogen bonds with each other
