Reactions of p3 oxides Flashcards
Na2O
1275
(solid) Ionic
“Dissolves” (i.e.
dissolves and then
reacts with water to
form a solution)
Na2O + H2O 2NaOH(aq)
The Na+ and O2- ions dissolves in water and then the O2- ions react with water:
O2- + H2O 2 OH-
PH IS 14
Na2O + 2 H+ 2Na+ + H2O
basic
MgO
2900
(solid) Ionic (higher melting point
than Na2O as the Mg2+ions
are smaller and higher
charged than Na+ )
“Slightly soluble”
(i.e. some dissolves
and then reacts with
water to form a
solution)
MgO + H2O Mg(OH)2(aq)
Some Mg2+ & O2- ions dissolve in water
(less soluble than Na2O due to higher
lattice enthalpy) and then the O2-
ions react with water:
O2- + H2O 2 OH-
10
MgO + 2H+ Mg2+ + H2O
basic
Al2O3
2040
(solid)
Ionic (not as high a melting
point as expected due to
some covalent character
due to polarising nature of
Al3+ ions)
Insoluble Insoluble due to very high lattice
enthalpy
Al2O3 + 6H+ 2Al3+ + 3H2O
Al2O3 + 2OH- + 3H2O 2 Al(OH)4
- amphoteric
SiO2
1610
(solid) Giant covalent Insoluble
Insoluble due to lattice of atoms linked
by strong covalent bonds that would
have to be broken
SiO2 + 2OH- SiO3 2- + H2O
(must be hot,
concentrated NaOH)
acidic
P4O10
580
(solid)
Simple
molecular
(but quite a
big molecule)
Reacts violently
P4O10 + 6H2O 4H3PO4
H2O molecules attach the + P atoms,
leading to the release of H+
ions from the water molecules.
0
P4O10 + 12OH- 4PO43- + 6 H2O
acidic
SO2
-75
(gas)
Simple
molecular
“Dissolves” (i.e.
dissolves and then
reacts with water to
form a solution)
SO2 + H2O H2SO3
H2O molecules attach the + S atoms,
leading to the release of H+
ions from the water molecules.
3
SO2 + 2OH- SO32- + H2O
acidic
SO3
17
(liquid?)
Simple
molecular
Reacts violently
SO3 + H2O H2SO4
H2O molecules attach the + S atoms,
leading to the release of H+
ions from the water molecules.
0
SO3 + 2OH- SO4 2- + H2O acidic
