Zusammenfassung der Ressource
GCSE AQA Chemistry 3
Organic Chemistry
- Reversible Reactions
- Products of reaction can react
to produce original reactants
- Reaches equilibrium
in closed system
- Amount of reactants &
products reach certain
balance & stay there
- Reactions taking place at same rate
- Temperature
- Raise temp.
- Endo reaction increases
- Lower temp.
- Exo reaction increases
- Pressure
- Raise pressure
- Encourages reaction which
produces less volume
- Lower pressure
- Encourages reaction which
produces more volume
- Catalyst
- Reaches equilibrium
faster but end up with
same amount of product
- Haber Process
- nitrogen + hydrogen --> ammonia (+ heat)
- Nitrogen from air - 78%
- Hydrogen comes from
natural gas/crude oil
- Reversible reaction -
reaches equilibrium
- Industrial conditions: 200
atmospheres, 450*C, iron catalyst
- Higher pressure favours forward reaction
- High as possible - high % yield
- Forward reaction - exo
- Increasing temp. will move equilibrium
wrong way - yield better at lower temp.
- Lower temp. = lower
rate of reaction
- 450*C is a compromise
- Iron catalyst speeds up
reaction & keeps costs down
- Alcohols
- General Formula:
Cn H2n+1 OH
- Flammable - burn in air to
produce CO2 & water
- Dissolve completely in
water --> neutral solutions
- React with sodium to give
hydrogen & alkoxides
- Used as solvents
- Can dissolve substances
water can't dissolve
- Ethanol - solvent
for perfumes
- Methylated spirit - ethanol, clean paint
brushes, poisonous, purply-blue dye added
- Used as fuels
- Ethanol in spirit burners
- Fuel for cars - renewable
- Carboxylic Acids
- Functional
group: -COOH
- Names end in -anoic acid'
- React like other acids with carbonates --> CO2
- Salts formed end in -anoate
- Dissolve in water to produce acidic solutions
- Ionise & release H+ ions - but don't ionise
completely --> weak acidic solutions
- Ethanoic acid dissolved in water - vinegar
- Citric acid - fizzy drinks, get rid of scale
- Longer chains -
soaps & detergents
- Esters
- Ethanoic acid - v. good
solvent but acidic
- Esters
- alcohol + carboxylic
acid --> ester + water
- Acid catalyst used
- Functional group: -COO-
- Have pleasant smells, volatile,
flammable, dangerous, don't mix v. well
with water, do mix well with alcohols
- Used in perfumes, to make flavourings, ointments & solvents for paint, ink, glue
- Problems...
- Inhaling fumes irritates
mucus membranes
- Heavier than air,
v. flammable
- Some toxic - health problems
with synthetic food additives?