reactions of alkenes

Question 1

what occurs in a reaction of alkene

Answer 1

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

Question 2

what is an alcohol

Answer 2

contaions an -oh group known as a hydroxyl group, which replaces one hydrogen in the structure of an alkane

Question 3

genmeral formula alcohols

Answer 3

CnH2n+1OH

Question 4

what to remember when naming an alcohol

Answer 4

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

Question 5

solubility of alcohols

Answer 5

soluble in water as the OH gropup allows alcohol molecules to form hydrogen bonds with water molecules

Question 6

polarity trend of alcohols

Answer 6

decreases as the molecule becomes larger because the length of the chain increases and more of the molecule is non-polar

Question 7

boiling point of alcohols compared to hydrocarbons

Answer 7

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

Question 8

trend of boiling point in alcohols

Answer 8

increases as the size of the alcohol molecule increases due to an ioncrease in dispersion forces

Question 9

how top name alcohols

Answer 9

name alkane as usual but then put a dash (-) the carbon number alcohol is bonded to (-) ‘ol’

Question 10

combustion of alcohols

Answer 10

readily undergo combustion when reacting with oxygen to form CO2 and H2O

Question 11

what are carboxylic acids

Answer 11

weak acids that are often present in food, giving it a sour taste, contain a carboxyl group (-COOH)

Question 12

general formula carboxylic acid

Answer 12

CnH2n + 1 COOH

Question 13

where are carboxylic acids found

Answer 13

some insect venoms, when food detiriorates,

Question 14

how to name carboxylic acids

Answer 14

keep regular alkane name, then remove suffic “an” and replace with -oic acid

Question 15

things to remeber when naming carboxylic acid

Answer 15

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

Question 16

why are carboxylic acids acids

Answer 16

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

Question 17

why to carboxylic acids have the highest boiling points

Answer 17

a dimer of two carboxylic acid monomers form two hydrogen bonds

Question 18

what is an ester

Answer 18

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

Question 19

general formula esters

Answer 19

R - COO - R’, where R and R’ are alkyl groups that may or may not be the same

Question 20

how are esters formed

Answer 20

when carboxylic acids are heated with alohols in the presence of suphuric acid (catalyst)

Question 21

what occurs during esterfication

Answer 21

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

Question 22

process of drawing ester reaction

Answer 22

1. 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

Question 23

how to name esters

Answer 23

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)

Question 24

boiling point of esters

Answer 24

lower boiling points than alcohols or carboxylic acids as they have no free hydroxyl groups so cannot form hydrogen bonds with each other

Question 25

polarity of esters

Answer 25

polar but dont form hydrogen boinds