Stuff from chem revision booklet Flashcards
equation for rate of reaction
rate of reaction = change in amount of a reactant or product/time
or
number of successful collisions / time
ways to measure how long it takes for a reaction to finish
how long it takes for…
cross to dissapear (solid sulfur precipitate)
magnesium piece to dissapear
how long it takes to produce a certain amount of gas (?)
if the reaction is exothermic, will the triangle H have a negative sign?
yess
advantages and disadvantages of ethene route to alcohol
fast, efficient, continuous process,relatively pure product
non renewable finite resource
disadvantages and advantages of fermentation
cheap and renewable resource (eg sugar cane)
slow reaction, poor quality products- eg low aqueous concentration <14%
industrial formation of ethanol
made from ethene and steam
high temp, high pressure and phosphoric acid catalyst needed
ethene combines with steam to make ethanol which is used as a solvent
process of fermentation
sugar solution + yeast warmed
airlock keeps air out
yeast respires anaerobically, releasing enzymes to catalyse the breakdown
C6H12O6 -> 2C2H5OH + 2CO2
what is polypropene used for
for plastic crates and ropes, as it is stronger and less flexible than polyehtene
what is polyethene used for
plastic bags and plastic bottles- forms a thin, flexible, transparent film
what is polytetrafluorene used for
non stick pans
what is PVC used for
drain pipes and insultion on electric cables since it is strong, not flexible and doesn’t conduct electricity
how do you calculate RF value
distance travelled by component/ distance travelledby solvent
substance + oxygen ->
oxide
metal + water ->
metal hydroxide + hydrogen
metal + acid->
salt+hydrogen
oxide + acid ->
salt+water
hydroxide+acid->
salt+water
carbonate+acid->
salt+water+co2
hydrogencarbonate+acid->
salt+water+co2
ammonia+acid->
ammonium salt
metal carbonate->
metal oxide+co2
precautions for toxic substances
wear gloves
if gas, use fume cupboard/well ventilated lab
precautions for corrosize substances
wear gloves to prevent burns
precautions for harmful substances
wash hands if spilt
precautions for irritant substances
wear gloves or wash hands if spilt