Group 17 Flashcards
Electron configuration
ns2 np5
Physical state at 298K
Fluorine - Pale yellow gas
Chlorine - Pale yellowish green gas
Bromine - Reddish Brown liquid
Iodine - Purplish-black solid
Colour intensity down the group due to
increases due to increase in metallic properties of elements
Physical properties
Simple diatomic molecule
reactive non-metal
not found in the elemental state in nature
nuclear charge
volatility
mp/bp
Solubility in water
constant
decrease
increase
sparingly soluble
Atomic and ionic radii down the group why
increase due to extra electron shells
Effective nuclear charge down the group
constant
volatility down the group and why
decrease due to increase in number of electrons and can de Waals forces
Solubility and exceptions and why
Sparingly soluble because they cant form hydrogen bond
Except for Iodine due to formation of water-soluble ion I3-
Fluoride because it can form hydrogen bonds
and chloric acid when exposed to strong sunlight
What is bond energy
Energy required to break a particular covalent bond per mole of the bond
bond energy down the group and exception
decrease due to increase in atomic radius making covalent bond longer and weaker
except Fluorine to Chlorine due to closeness of atoms which result in repulsion between non-bonding electron
Oxidising strength of group 17 in general and down the group
All powerful oxidising agents and oxidising strength decrease down the group
What is oxidising strength indicated by
positive standard electrode potentials
Halides react with hydrogen to form
Hydrogen halide
What is reaction between hydrogen and halide
redox reaction
Reaction of group 17 elements with hydrogen
Fluorine - Explosive in light and dark
Chlorine - Explosive in bright sunlight
Bromine - Needs heat and catalyst
Iodine - needs heat catalyst (nickel or platinum) and is reversible
Boiling point of hydrogen halides down the group and exception and explanation
Increase down the group due to total number of electrons increase causing intermolecular van der Waals forces to get stronger
HF is higher than HCl due to strong intermolecular hydrogen bonds
What happens to hydrogen halides on heating
Decompose to their elements (Split hydrogen from halogen)
What happens during decomposition
Covalent bond between hydrogen and halogen breaks
Thermal stability of Hydrogen halides down the group and reason
Decrease as covalent bonds get longer and weaker
Only hydrogen halide that is considered stable and reason
Hydrogen Fluoride due to strong hydrogen bonds
When platinum wire is introduce in jar of hydrogen iodide gas what happens
Purple fume released which is iodine vapour formed by decomposition of hydrogen odide
What is produced when chlorine reacts with sodium hydroxide
Sodium chloride and sodium chlorate (I) is produced (+water)
What reaction is the reaction between chlorine reacts with sodium hydroxide and what is it
disproportionation reaction where chlorine is reduced to chloride but oxidised to sodium chlorate(I) at the same time.
What is produced when concentrated chlorine reacts with sodium hydroxide at 70C
Sodium chloride and sodium chlorate (V) is formed
What is formed when silver nitrate reacts with halide ions
Coloured precipitate - Silver halide or AgX
What happens to AgCl and AgBr when dissolves in ammonia solution
form colorless solution
AgCl
Colour
Solubility in diluted ammonia
Solubility in concentrated ammonia
White
Soluble
Soluble
AgBr
Colour
Solubility in diluted ammonia
Solubility in concentrated ammonia
Cream
Insoluble
souluble
AgI
Colour
Solubility in diluted ammonia
Solubility in concentrated ammonia
Yellow
Insoluble
Insoluble
Solid halide heated with concentrated sulphuric acid forms what
Hydrogen halide
What happens when KBr KI experienced prolonged heating with concentrated sulphuric acid
Hydrogen halide further oxidises into halide + Sulphur Dioxide +Water
Solid halides and their reaction with concentrated H2SO4 (colour)
NaCl - White fumes
KBr - White fumes and reddish brown fumes after prolonged heating
KI - White fumes +violet fumes after prolonged heating
What is used to convert KBr and and KI into hydrogen halide
concentrated phosphoric acid H3P4
