topic 4
the most reactive metals will react with cold water to form , metal hydroxide
fairly reactive metals will react with acid to form, metal + acid = salt + hydrogen
all metals will react with oxygen thought some faster than other to form, metal oxide
the only metal that does not reactive with o2, acid or H2o is gold as it is extremely unreactive
You can see if one metal is more reactive than another by using displacement reactions
Easily seen when a salt of the less reactive metal is in the solution
More reactive metal gradually disappears as it forms a solution
Less reactive metal coats the surface of the more reactive metal
Oxidation
Is
Loss
Reduction
Is
Gain
( of electrons )
OILRIG
REDOX
metals form positive ions, if it does this easier it means that it is a more reactive metal
potassium
sodium
lithium
calcium
magnesium
zinc
iron
copper
most metals are extracted from ores in the earths crust
and unreactive metals are uncombined elements
OXidation is GAIN of OXygen
reduction is LOSS of oxygen
Metals less reactive than carbon can be extracted from their oxides by reduction with carbon
reduction involves the loss of oxygen, so you are reducing the ores to remove the oxygen to obtain the pure metal
the carbon displaces the metal from its ore
if a metal is more reactive than carbon electrolysis must be used
Phytoextraction
Some plants absorb metal compounds through their roots
They concentrate these compounds into their shoots and leaves
The plants can be burned to produce an ash that contains the metal compounds
Bacterial extraction
Some bacteria absorb metal compounds
produce solutions called leachates
scrap iron can be used to obtain metals from the leachate
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less reactive a metal is, the more resistant it is to oxidation, because for a metal to react, it forms a positive metal ion by losing electrons (loss of electrons=oxidation)
Relative resistance to oxidation is the same as relative resistance to losing electrons / forming positive metal ions
Relative resistance to oxidation is the same as relative resistance to losing electrons / forming positive metal ions
recycling is key as it allows sustainable develpoment
reversible reactions - the products can react to form the original reactants
The Haber Process: nitrogen + hydrogen ⇌ ammonia
equilibrium:rate of forward reaction = rate of backward reaction
concentration of reacting substances stay the same
dynamic equilibrium: once the forward and backward reaction reach equilibrium, they keep going
the Haber process
high pressure (about 200 atmospheres).
high temp (about 450 °C)
catalyst of iron
nitrogen for the air
hydrogen from natural gases
if a condition of a system at equilibrium changes that that will change to oppose that change - le chandelier's principle
increase temp
increase concentraition
increase pressure
the position of equilibrium will move to the side with the least moles to balance it out
the side that does not already that that thing
towards to endothermic reaction