Physical Unit 2.4: Properties of P3 Elements & their Oxides Flashcards
what is the bonding & structure of Na?
bonding: metallic bonding
structure: giant lattice of +ve metal ions surrounded by -ve delocalised e-s
what is the bonding & structure of Mg?
bonding: metallic bonding
structure: giant lattice of +ve metal ions surrounded by -ve delocalised e-s
what is the bonding & structure of Al?
bonding: metallic bonding
structure: giant lattice of +ve metal ions surrounded by -ve delocalised e-s
what is the bonding & structure of Si?
bonding: covalent
structure: macromolecular
giant lattice
what is the bonding & structure in phosphorus?
P4
bonding: covalent
structure: simple molecular
what is the bonding & structure in sulfur?
S8
bonding: covalent
structure: simple molecular
what is the bonding & structure in chlorine?
Cl2
bonding: covalent
structure: simple molecular
what are the observations & equation for the reaction of Na & water?
observations: fizzes, floats, moves on surface, melts, leaves alkaline trail (may catch fire with yellow-orange flame)
equation:
Na + H2O –> NaOH + 1/2H2
pH 14
what are the observations & equations for the reaction of Mg & water (l) & (g)?
observations with H2O(l): slow, bubbles on surface of Mg
with H2O (g)/steam: bright white light, forms white solid
equation with H2O(l):
Mg + 2H2O(l) –> Mg(OH)2 + H2
pH 9-10
with H2O(g):
Mg + H2O(g) –> MgO + H2
what are the observations & equations for the reaction of Cl2 & water (with & without sunlight)?
observations without sunlight: nvc, if add UI paper, turns from red to white
with sunlight: bubbles
equation without sunlight:
Cl2 + H2O –> HClO + HCl
with sunlight:
2Cl2 + 2H2O –> O2 + 4HCl
what are the observations & equation for the reaction of Na & oxygen?
observations: yellow-orange flame, white solid formed
equation:
2Na + 1/2 O2 –> Na2O
what are the observations & equation for the reaction of Mg & oxygen?
observations: bright white light, white solid forms
equation:
Mg + 1/2 O2 –> MgO
what are the observations & equation for the reaction of Al & oxygen?
observations: bright white light, white solid forms
equation:
2Al + 3/2 O2 –> Al2O3
what are the observations & equation for the reaction of Si & oxygen?
observations: bright white light, white solid forms
equation:
Si + O2 –> SiO2
what are the observations & equation for the reaction of phosphorus & oxygen?
observations: bright white light, white solid forms
equation:
P4 + 5O2 –> P4O10
what are the observations & equation for the reaction of sulfur & oxygen?
observations: blue flame, white solid forms
equation:
S + O2 –> SO2
what is the structure of Na2O?
ionic
Na+ & O2- ions
what is the structure of MgO?
ionic
Mg2+ & O2- ions
higher mp than Na2O as Mg2+ ions are smaller & have higher charge than Na+ ions
what is the structure of Al2O3?
ionic but w large degree of covalent character as Al3+ is small & highly charged
what is the structure of SiO2?
covalent macromolecule
what is the structure of P4O10?
covalent molecular
what is the structure of SO2?
covalent molecular
what is the structure of SO3?
covalent molecular
describe what happens when Na2O reacts with water, give the equations & pH of the solution formed
what happens: dissolves then O2- ions react
equations:
Na2O + H2O –> 2NaOH
O2- react with water: O2- + H2O –> 2OH-
pH: 14
describe what happens when MgO reacts with water, give the equation & pH of the solution formed
what happens: slightly soluble, few O2- ions
equations:
MgO + H2O –> Mg(OH)2
O2- + H2O –> 2OH-
fewer O2- than Na2O so less alkaline
pH: 9-10
describe what happens when Al2O3 reacts with water, give the equation & pH of the solution formed
what happens: insoluble due to high lattice enthalpy
equations: n/a
pH: 7 (pH of water bc insoluble)
describe what happens when SiO2 reacts with water, give the equation & pH of the solution formed
what happens: insoluble due to v many v strong covalent bonds
needs lots of heat energy to break
equations:
pH: 7
describe what happens when P4O10 reacts with water, give the equation & pH of the solution formed
what happens: violent reaction
equations:
P4O10 + 6H2O –> 4H3PO4
strong acid, fully dissociates
pH: 0
describe what happens when SO2 reacts with water, give the equation & pH of the solution formed
what happens: dissolves & reacts
equations:
SO2 + H2O –> H2SO3
weak acid
pH: 3
describe what happens when SO3 reacts with water, give the equation & pH of the solution formed
what happens: violent reaction
equations:
SO3 + H2O –> H2SO4
strong acid, fully dissociates
pH: 0
how does Na2O react with acids & alkalis & what is the nature of the oxide?
reaction with acids:
Na2O + 2H+ –> Na+ + H2O
with alkalis: n/a
nature of oxide: basic
how does MgO react with acids & alkalis & what is the nature of the oxide?
reaction with acids:
MgO + 2H+ –> Mg2+ + H2O
with alkalis: n/a
nature of oxide: basic
how does Al2O3 react with acids & alkalis & what is the nature of the oxide?
reaction with acids:
Al2O3 + 6H+ –> 2Al3+ + 3H2O
Al2O3 + 6H+ + 9H2O –> 2[Al(H2O)6]3+
with alkalis:
Al2O3 + 2OH- + 3H2O –> 2[Al(OH)4]-
nature of oxide: amphoteric
how does SiO2 react with acids & alkalis & what is the nature of the oxide?
reaction with acids: n/a
with alkalis:
SiO2 + 2OH- –> SiO32- + H2O
nature of oxide: acidic
how does P4O10 react with acids & alkalis & what is the nature of the oxide?
reaction with acids: n/a
with alkalis:
P4O10 + 12OH- –> 4PO43- + 6H2O
nature of oxide: acidic
how does SO2 react with acids & alkalis & what is the nature of the oxide?
reaction with acids: n/a
with alkalis:
SO2 + 2OH- –> SO32- + H2O
nature of oxide: acidic
how does SO3 react with acids & alkalis & what is the nature of the oxide?
reaction with acids: n/a
with alkalis:
SO3 + 2OH- –> SO42- + H2O
nature of oxide: acidic
what is the structure of phosphoric(V) acid & its oxo-anion?
see booklet
tetrahedral 109.5
in reality all P-O bonds are the same length in phosphate ions due to delocalisation (similar to in benzene)
what is the structure of sulfuric(IV) acid & its oxo-anion?
see booklet
107
pyramidal
what is the structure of sulfuric(VI) acid & its oxo-anion?
see booklet
109.5
tetrahedral
