Unit four JCL Flashcards
Group 1 metals oxidation state
always +1
Group 2 metals oxidation state
always +2
Oxygen oxidation state
usually -2 (except in peroxides, where it is -1 and F2O, where it is +2)
Hydrogen oxidation state
usually +1 (except in metal hydrides, where it is -1)
Fluorine oxidation state
always -1
Chlorine oxidation state
usually -1 (except in compounds with O or F)
What increases as you go down group 2
Reactivity, Atomic Radius, Reaction with water, Solubility of Hydroxide
What decreases as you go down group 2
1st ionization energy, Melting point, Solubility of Sulfate
What are oxidizing agents
They cause anther species to be oxidized by taking electrons, The oxidizing agents themselves are reduced
What is a displacement reaction
A reaction in which a more reactive element displaces a less reactive element from an aqueous solution of its ion
What colour is the water and cyclohexane for Cl2
water: pale-green
cyclohexane: pale-green
What colour is the water and cyclohexane for Br2
water: Orange
cyclohexane: Orange
What colour is the water and cyclohexane for I2
water: Brown
cyclohexane: Violet
What is a disproportionation reaction
A redox reaction in which the same element is both oxidised and reduced
Identifying halide ions, precipitate colour
AgCl: white
AgBr: cream
AgI: yellow
Identifying halide ions, solubility of silver halide solution in NH3
AgCl: soluble in dilute NH3 (ammonia)
AgBr: soluble in concentrated NH3
AgI: insoluble in concentrated NH3
What is the trend in oxidising power down group seven?
It decreases
Test for carbonate ion?
Put in dilute acid, bubble through lime water, turns cloudy
Test for sulphate ion?
Add barium chloride, forms white precipitate
Test for ammonium ion?
Add sodium hydroxide and heat, red litmus paper will turn blue from ammonia gas produced
Define first ionization energy
The first ionization energy of an element is the energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions
Define successive ionisation energy
Successive ionization energies of an element are a measure of the energy required to remove each electron in turn
How does electron shielding effect ionization energy?
More inner shell electrons –> greater distance –> less nuclear attraction on outer shell electrons
How does atomic radius effect ionization energy?
Greater radius –> less nuclear attraction on outer shell electrons
How does nuclear charge effect ionization energy?
Greater nuclear charge –> greater attractive force on the outer shell electrons
Why is there a drop in first ionization energy between p and s?
The electrons are in a new sub-shell that is higher in energy so it takes less energy to remove an electron
Why is sodium described as an s-block element?
Its outermost electron is in the s sub-shell
What is metallic bonding?
The electrostatic attraction between po0sitive metal ions and delocalized electrons
What does delocalized mean?
Electrons are free to move and are not fixed to one specific ion/atom
What does the word lattice mean?
A regularly repeating pattern
What is a giant metallic lattice?
A 3D structure of regularly arranged positive ions in a sea of delocalized electrons bonded by strong metallic bonds
Melting/ boiling point in metals
High melting and boiling points
Electrical conductivity in metals
Good conductivity
Physical manoeuvability
Malleable and ductile
Malleable definition
Can be hammered into shape
Ductile definition
Can be drawn out into wires
Why do metals have high melting and boiling points
Strong electrostatic attraction between positive metal ions and negative electrons, metallic bonds require high amounts of energy to break apart
Why are metals good conducters
Delocalized electrons are free to move across the metallic lattice and can carry a charge in a uniform direction producing a current
Why are metals malleable and ductile?
Delocalized electrons can move and layers in the giant metallic lattice are able to slide over each over
