Elements of the sea Flashcards
(46 cards)
at the cathode the molecule…
accepts electrons
at the anode the molecule…
loses its electrons
chlorine can displace ____ and ____ because it is…
bromine and iodine
more reactive
what is the equation for chlorine displacing bromine?
2Br- (aq) + Cl2(aq) —> Br2(g) + 2Cl-(aq)
what is the equation for chlorine displacing iodine ?
2I- (aq) + Cl2(aq) —> I2(aq) + 2Cl-(aq)
what is brine
a solution of water with a high concentration of salts
all uncombined elements have an oxidation number of…
zero
the oxidation number of a monatomic ion is…
the same as it’s charge
for a neutral compound the overall oxidation state is…
zero
roman numerals tells you…
the oxidation state
the oxidation will _______________ for every election gained
decrease by one
the oxidation state will _____________ for every election lost
increase by one
reducing agents are…
oxidised
oxidising agents are…
reduced
what type of titration is used for finding the concentration of an oxidising agent?
iodine-sodium thiosulfate
what is the equation for when in the ions in iodine-sodium thiosulfate titration react?
I2 (aq) + 2S2O3^2- (aq) —> 2I- + S4O6^2- (aq)
what is the original equation for the sodium-iodine thiosulfate titration?
IO3 - + 5I- + 6H+ —> 3I2 + 3H2O
halogens get less reactive…
because..
down the group
as you go down the group atoms get larger so outer electrons are more shielded and having greater atomic radius making is harder to attract electrons to form an ion
halogens can displace..,
halide ions from solution
chlorine will displace ….
bromide and iodine
bromine will displace….
but not…
iodine
chlorine
iodine won’t displace…
bromine or chlorine
if bromide is displaced and formed you will see…
a colour change to orange
if iodine is displaced and formed you will see…
a colour change to brown
