halogens Flashcards
what is the trend in bp and mp of halogens and why
bp and mp increases down the group as theres more electrons so stronger london forces which requires more energy to break them
state and colour of halogens at room temp
fluorine- pale yellow gas
chlorine- pale green gas
bromine- red-brown liquid
iodine- grey solid
state colour of halogen in aqueous solution of water
chlorine- pale green solution
bromine- yellow solution
iodine- brown solution
what is a halide
a binary compound of a halogen
why must experients with halogen be done in a well ventilated area
they are powerful oxidising agents and toxic
what is the trend in reactivity down group 7
reactivity decreases as
atomic radius increases
sheilding increases
nucleur charge increases but doesnt outweigh the effect of increase in sheliding and atomic radius
therefore halogen become weaker oxidising agents down the group
what will the halogens look like when cyclohexane is added
chlorine- pale green
bromine- yellow
iodine- violet
whaf is displacement of group 7 elements
more reactive halogen displacing less reactive halide fron it’s aqueous solution
what is disproportionation and what can it happen with
a reaction where the same element is both oxided and reduced
any halogen except fluroine as its a powerful oxidising agent
how does chlorine react with water
Cl2(g) + H20(l) —> HCI(aq)+ HOCI(aq)
how is bleach formed, why this way and what is used as bleach
by reacting chlorine with cold dilute sodium hydroxide solution as it has a high solubility
Cl2(aq) + 2NaOH(aq) —> NaCIO(aq) + NaCI(aq) + H20(l)
The mixture of NaCIO is used as bleach. The NaCIO is just called sodium chlorate (1).
give 1 pro and 1 con of adding chlorine to water
it kills bacteria
it could form chlorinated hydrocarbons which are toxic and carcinogenic
why will chlorine and water bleach universal indicator
the ClO- ion fron HOCl produced is a powerful oxidising agent
