SC10 + 11 Flashcards
what is an electolyte
an ionic solid which is moltem or dissolved in water
what is electolyisis
when electricity is used to decompose atoms
what are the 3 phrases to remember
P poistive
A anode
N negative
I s
C cathode
O xidation
At
Anode
Reduction
At
Cathode
Oxidation
Is
Loss
Reduction
Is
Gain
list the reactivity series
Pottasium
Sodium
Calcium
magesium
aluminium
(copper)
zinc
iron
copper
silver
gold
what is an ore
a rock containing enough of a compound to extract metal for profit
how are metals from zinc - copper extracted from ores
by heating them with carbon which is more reactive and displaces them
how are alumminium and above extracted from ores
through a more powerfu;; method of electrolysis which involves passing electricity through a molten ionic compund to decompose it into its elements but a lot of energy is needed for this so it is extremly expensive
what is bioleaching
uses bacteria grown on a low grade ore
the bacteria produce a solution containing the metal ions called a leachate
the metal is then extracted from the leachate by displacement and then purifying through electrolysis
what is phytoextraction
involves growing plants which absorb metal compounds and then burning them into ash where the metal is them extracted
what are redox reactions
oxidation- the gain of oxyden by a compound
reduction - the loss of oxygen by a compound
what is corrosion
whn a metal reacts with oxygen making the metal weaker
the metal gains oxygen and so is oxidied
the corrsosion of iron requires water and is called rusting
the more reactive a metal the more rapidly it corrodes
some metals corrode quickly but form a layer of protective oxide which prevents further corrosion
what is a life cycle assesment
carried out to work out the enviromental impact of a product
helps people decide if it is worthwile to recycle a product
what is a reversible reaction
in some chemical reactions the products react to form the reactants
a double arrow is used to show both fowards and backwards reactions occur at the same time
what is dynamic equlibrium
dynamic equilibrium is when at a certain point the forwards and backwards reactions are still occuring but the percentages of them are no longer changing
it only occurs in closed systems
what is the haber process
how ammonium is manufactured
a reversible reaction between nitrogen from the air and hydrogen from natural gas
the dynamic equilibrium position can be shifted by reaction conditions
ammonium condition are famously chosen to make a large amount as cheaply as possible
