Inorganic Chemistry- Group 7 Flashcards
Chlorine
Colour
State at room temp
Colour of aqueous solution
Colour in cyclohexane
Colour: Green
State at room temp: Gas
Colour of aqueous solution: Pale green
Colour in cyclohexane: Pale green
Bromine
Colour
State at room temp
Colour of aqueous solution
Colour in cyclohexane
Colour: Brown
State at room temp: Liquid
Colour of aqueous solution: Orange
Colour in cyclohexane: Orange
Iodine
Colour
State at room temp
Colour of aqueous solution
Colour in cyclohexane
Colour: Black
State at room temp: Solid
Colour of aqueous solution: Brown
Colour in cyclohexane: pink/purple
Define oxidising agent
Accepts electrons
Why are halogens oxidising agents?
They accept electrons to form halide ions
Define disproportionation
The same element is being reduced and oxidised
Reaction of chlorine with water
Cl2 + H2O ->/<- HCl + HClO
Observation
Chlorine
HCl
HClO
Chlorine- pale green solution
HCl- turns litmus paper red
HClO- bleaches litmus paper
Reaction of chlorine with water in sunlight
Cl2 + H2O -> 2HCl + 1/2O2
Benefits and risks of using chlorine in water treatment
Kills bacteria
Toxic in large quantities
Reaction of chlorine with NaOH
Cl2 + 2NaOH -> NaCl + NaClO + H2O
Test for halide ion
Add dilute AgNO3
Add silver nitrate solution
What dissolves in dilute ammonia?
Just silver chloride
What dissolves in excess ammonia?
Silver chloride
Silver bromide
Define a reducing agent
Donates electrons
Why are halides reducing agents?
They donate electrons to become halogens
Observation of SO2
Chocking acidic gas
Observation of S
Yellow solid
Observation of H2S
Gas with bad egg smell
Acid base observation of halides reacting with concentrated H2SO4
Steamy white fumes
Chlorine and H2SO4
NaCl + H2SO4 -> NaHSO4 + HCl
What does the H2SO4 act as in the acid base reaction?
Acid
What does the H2SO4 act as in the redox reaction?
Oxidising agent
