CHAPTER 10 Flashcards
what is a functional group
it is what gives a family of compounds their characteristics reactions
what is the functional group of an alkene
the c=c bond
what is a homologous series
a family of an organic compounds with the same functional group
why aren’t alkenes used as fuels
they commonly combust incompletely which releases much less energy
functional group of alcohols
OH-
where do you find the OH- on an alcohol molecule
on the very right
first four components of the alcohol series
methanol
ethanol
propanol
butanol
functional group of carboxylic acid
-COOH
first four carboxylic acid
methanoic acid
ethanoic acid
propanoic acid
butanoic acid
functional group in esters
-COO-
how is ethanol produced
fermentation
how is ethene obtained
cracking crude oil
how is ethanol made
reacting ethene with steam in the presence of a catalyst
what property makes alcohols useful as solvents
they dissolve many other substances
3 uses of alcohols
perfumes
mouthwash
aftershave
what is produced when an alcohol combusts
carbon dioxide
and water
what is produced when an alcohol is mixed with sodium
sodium ()oxide and hydrogen
what is produced when an alcohol is oxidised
a carboxylic acid and water
general formula of alkenes
Cn H2n
what are alkenes
hydrocarbons with a double c=c bond
what makes alkenes unsaturated
the double c=c bond bond means that they have two fewer hydrogen compared to the alkenes with the same number of carbons
what are the first four alkenes and how many carbons do they have
ethene 2
propene 3
butene 4
Pentene 5
what is produced when alkenes combust completely
water and carbon dioxide
what happens when alkenes burn in air and why
they undergo incomplete combustion there isn’t enough oxygen
what is produced during incomplete combustion 4
water, carbon dioxide, carbon and carbon monoxide
why are alkanes used as fuels
they combust completely and release more energy
what happens when alkenes burn
incomplete combustion burn with a smoky yellow flame
why are alkenes unsaturated
the double c=c bond means they don’t have the maximum amount of hydrogens
what is hydrogenation
the addition of hydrogen
what happens when hydrogen is added to an alkene
the equivalent saturated alkane is formed
what catalyst is used for hydrogenation
nickel
why is hydrogenation used
it increases the melting point of oils so things like margarine can be spread easily
what must ethene react with to produce ethanol
steam
process of making ethanol
ethene is mixed with steam water is added across the double dons
it is passed over a catalyst alcohol formed
what is important to remember about the reaction of ethene and steam to make ethanol
it is reversible
process of purifying alcohol
the reaction mixture is passed into a condenser
ethanol and water have a higher boiling point than ethene so they both condense whilst any unreacted ethene gas is recycled back into reactor
it is then purified
what happens to the colour of the mixture when an alkene and halogen react
the ethene takes the colour so the mixture becomes colourless
how can bromine be used to test for alkenes
when orange bromine water is added to an alkene, dibromoethane will be formed, which is colourless
what are the molecules like that are formed when an alkene and bromine react
they are saturated and colourless
functional group of alcohols
-OH
general formula of an alcohol
Cn H(2n+1) OH
the first for alcohols and their formulas
methanol (CH3OH)
ethanol (C2H5OH)
propanol (C3H7OH)
butanol (C4H9OH)
what is the main acid in vinegar and which homologous group does this belong to
ethanoic acid
carboxylic acids
functional group of carboxylic acid
-COOH
first 4 carboxylic acids and their formulas
methanoic acid (HCOOH) ethanoic acid (CH3COOH) propanoic acid (C2H5COOH) butanoic acid (C4H7COOH)
functional group of an ester
-COO-
how is an ester formed
when an alcohol and a carboxylic acid react
which type of catalyst is normally used to make esters
acid
formula for creation of esters
alcohol + carboxylic acid -> ester+ water q
what is produced when carboxylic acids dissolve in water
an acidic solution
which is the ester we must know
ethyl ethanoate
what is produced when a carboxylic acid reacts with a carbonate
salt, water and carbon dioxide
when a carboxylic acid reacts with a carbonate to produce a salt , what will the name end in
ethanoate
example of a carboxylic acid + carbonate reaction
ethanoic acid + sodium carbonate -> sodium ethanoate + water + carbon dioxide
why are esters used in perfumes and food flavourings 2
they smell fruity and are volatile
general equation for formation of an ester
carboxylic acid + alcohol -(acid catalyst )-> ester + water
why is carbon dioxide given off slowly when a carbonate reacts with carboxylic acid
they are weak acids
why must acids dissolve in water before they show their acidic properties
in water, all acids will ionise (split up )
why is carbon dioxide given off slowly when a carbonate reacts with a carboxylic acid
they are weak acids
what is produced when acids ionise 2
H+ ions and negative metal ions
what is it that turns a solution acidic
H+ ions
what makes an acid weak
it doesn’t completely ionise
why are carboxylic acids weak
they don’t ionise completely so they only form weak acidic solutions
they have fewer H+ ions so react more slowly with carbonates
how is ethanol made
fermentation
process of fermentation
an enzyme in yeast converts sugars to ethanol
equation for fermentation
sugar -(yeast)-> ethanol + carbon dioxide
conditions needed for optimum fermentation 3
37 degrees
slightly acidic solution
anaerobic conditions
why does fermentation have optimum conditions
it is when the enzyme in yeast works best
another way of creating ethanol
react ethene and steam in the presence of a catalyst
why are alcohols used as solvents
they dissolve everything water can and more
why are alcohols used as fuels
they burn fairly cleanly and don’t smell
what is produced when an alcohol combusts in air
carbon dioxide and water
what is the reaction of sodium and an alcohol similar to
reaction of sodium and water
what observations can be made when sodium reacts with 2
sodium produced hydrogen
gets smaller and smaller
what is produced when the first four alcohols react with water
they are soluble and produce a neutral solution
how are carboxylic acids produced
alcohols are oxidised in air
why do bottles of wine taste like vinegar when left open for too long
the oxygen oxidises the alcohol to produce ethanoic acid (vinegar )