unit 5 Flashcards
base
used to neautralise -metal oxides
calcium oxide
used to neutralize acidic soil
when acid ionises-
when alkali ionises-
produces H+
produces OH
alkali+water
water and salt
metals form
basic oxides and hydroxides
non metals form
acidic oxides
alumina
aluminium reacted with oxygen found in mineral bauxite
extracted and purified using bayar process
stages of bayar process
crush bauxite
filter impurities
allow to crystalize to form alumina
neutralize nitric acid
using calcium hydroxide
extraction of alumina
molten alumina is electrolysed using haul haroult process
croyolite
is added to lower melting point and save energy
electrolysis
spliting chemicals into their elements by passing electrical current
diaphram cell
porous so it allows brine to pass from one side to another but prevents chlorine and hydrogen gas from passing through so gasous produts are kept separated but still mixed with brine
membrane cell
has an ion exchange membrane diving the cell .allows posituve ions but wont allow negative to pass through from the anode to catode as the brine only enter the cell the from the anode
why is sodium hydroxide formed at the membrane cell more purified than diaphragm cell
contaminated with sodium chloride
transition metals
d block and is an element with a partially filled d orbital
uses of transition metals
good catalysts
used to indicate oxidation
isomer
same molecular formula but different structure
why are alkenes more reactive than alkanes
there is a greater electron density in the double bond so more like to react
unequal spitting
known as heterolysis
equal splitting
radical =equal
homolysis
condition for alkanes halogen to take place
uv light
sunlight
initiation
propagation
termination
- radicals create
- radicals are genearated
- radicals removed
entalphy change
when one mole of gasous gas is dissolved in water under standard condition
standard enthalphy of combustion
when 1 mole of a substance reacts completly with oxygen under standard conditions
standard enthalphy of neutralisation
when one mole of water is formed in a neutralusation reaction under standard condition
standard enthalphy of formation
when one mole of a compound formed from its element under standard condition
how transition metals are used as catalysts
ability to change oxidation state
lower activation energy
speed up reaction
benefits of using catalysts to crack hydrocarbns
uses less energy
highter yield of alkanes
can reuse
exothermic
releases energy from the system as a form of heat
energy released from the system to the surroundings
reaction in from of electricity
endothermic
absorbs energy from the surroundings in the form of heat
energy is in the form of heat
