Periodicity Flashcards
produce a table with halide reactions with silver nitrate, dilute and concentrated ammonia
what are the products of halide reactions with sliver nitrate + the names of the products?
Cl- + Ag+ -> AgCl (silver chloride)
Br- + Ag+ -> AgBr (silver bromide)
I- + Ag+ -> AgI (silver iodide)
why is ammonia solution added after the sliver nitrate?
to confirm which halide it is as the colours look too similar in sliver nitrate
produce a table to show the colours of halogens in aqueous (water) and organic (cyclohexane) solvents
halogen aqueous organic
Cl- green green
Br- orange orange
I- brown violet
produce a table that shows halogen and halide displacement
in organic:
Cl2 + Br- = orange
Cl2 + I- = violet
Br2 + I- = violet
describe the halogens’ reactivity as you go down the group
less reactive as you go down the group.
radius increases
shielding increases
therefore the nuclear attraction on the outermost electron and on gaining an electron is weaker.
what is the displacement rule between halogen and a halide?
if halogen is more reactive, it’ll displace and oxidise the halide
describe the redox reactions of chlorine
1) it is added to drinking water to kill bacteria
Cl2 + H20 -> HClO + HCl (disproportionation)
2) household bleach
Cl2 + 2NaOH -. NaClO + NaCl + H20
(disproportionation)
what are the colours and states of the halogens at room temp?
Cl2= pale green gas
Br2 = orange / brown liquid
I2= grey/black solid
why are halogens more soluble in non-polar solvents than in water?
like dissolves in like
why does the boiling point of the halogens increase down the group?
electron number increases, meaning the IDD forces get stronger, requiring more energy to break
why is chlorine an oxidising agent?
because it can oxidise other substances by gaining their electrons (oxidation number decreases) and being reduced
what is the definition of periodicity?
repeating patterns across a period
sketch a graph of boiling points of period 3.
1) why does bpt increase from Na to Al?
2) why does Si have the highest bpt?
3) why does S have a higher bpt than P?
1) from Na to Al, the ion charge increases, 1+, 2+ and 3+, so there are more delocalised electrons, and stronger metallic bonds which require more energy to break
2) it is a giant covalent lattice which has strong covalent bonds between Si atoms, which are stronger than metallic bonds or IDD forces, they require the most energy to break
3) S8 has more electrons than P4, therefore stronger IDD forces
why are group 2 metals reducing agent?
they lose 2 electrons and are oxidised
