period 3 Flashcards
what is the reaction when sodium reacts with water
Sodium reacts with cold water. It fizzes
around on surface etc.
2 Na (s) + 2 H2O (l) 2 NaOH (aq) + H2
(g)
what is the reaction when magnesium reacts with cold water
Magnesium reacts very slowly with cold water to form the
hydroxide but reacts more readily with steam to form the oxide
Mg (s) + H2O (g) – >MgO (s) + H2
(g)
what is the reaction with sodium and oxygen
4 Na (s) + O2 (g) – >2 Na2O (s)
what is the reaction when magnesium reacts with oxygen
2Mg (s) + O2(g) –> 2MgO (s)
what is the reaction when aluminium reacts with oxygen
4Al (s) + 3O2(g) –> 2Al2O3 (s)
what is the reaction when silicon reacts with oxygen
Si (s) + O2(g) –>SiO2(s)
what is the reaction when phosphorus reacts with oxygen
4P (s) + 5O2 (g) –>P4O10 (s)
what is the reaction when sulfur reacts with oxygen
S (s) + O2(g) –> SO2(g)
what are the flame tests for all the period 3
Sodium burns with a yellow flame to produce a white solid.
Mg, Al, Si and P burn with a white flame to give white solid smoke.
S burns with a blue flame to form an acidic
choking gas.
what forms metal oxides
Na2O, MgO, Al2O3
describe the bondings of the period three metal oxides
They have high melting points. They have ionic giant
lattice structures: strong forces of attraction between
oppositely charged ions : higher mp.
They are ionic
because of the large electronegativity difference
between metal and O
describe the melting point trend as the period 3 metal oxides progress
The increased charge on the cation makes the ionic
forces stronger (bigger lattice enthalpies of
dissociation) going from Na to Al so leading to
increasing melting points.
how does Al2O3 show covalent character
Al2O3 is ionic but does show some covalent character.
This can be explained by the electronegativity difference being less big or alternatively by the small aluminium ion with a high charge being able to get
close to the oxide ion and distorting the oxide charge
cloud.
what period three oxide is macro molecular
SiO2
describe SiO2 as a macromolecule
SiO2 is macromolecular: It has many very strong
covalent bonds between atoms. High energy needed to break the many strong covalent bonds
what period three oxides are simple molecules
P4O10 (s), SO2 (g
metal oxides react with water to from
metal hydroxides
what is the reaction of sodium oxide with water
Na2O (s) + H2O (l) –> 2Na+(aq) + 2OH- (aq) pH 13
(This is a vigorous exothermic reaction)
what is the reaction of magnesium oxide with water
MgO(s) +H2O —> Mg(OH)2
What happens when phosphorus oxide reacts with water
P4O10 +6H2O —> 4H3PO4 (aq) PH 0
Describe reaction when SO2 reacts with H2O
SO2 +H2O —> H2SO3 (aq)
PH 3
What happens when SO3 reacts with water
SO3 + H2O —> H2SO4
Why does Al2O3 and SiO2 not react with water
Does not dissolve in water because of the high strength of the Al2O3 ionic lattice and the SiO2 macromolecular structure
PH 7
What type of reactions are period three oxides involved in
Acid base reactions
What happens when sodium oxide reacts with HCl
Na2O + 2HCl —> 2NaCl +H2O
What happens when Na2O +H2SO4
Na2O + H2SO4 —> Na2SO4 + H2O
What aluminium oxide is amphoteric
Aluminium oxide
What happens react when Al2O3 +6HCl
Al2O3 +6 HCl —> 2ALCl3 +3H2O
What happens when Al2O3 reacts with H2SO4
Al2O3 + 3 H2SO4 —> Al2(SO4)3 + 3H2O
What is the reaction when Al2O3 + 2 NaOH +3 H2O
Al2O3 +2NaOH + 3H2O—> 2NaAl(OH)4
What happens when P2O10 reacts with sodium hydroxide
P4O10 + 12NaOH—> 4Na3PO4 +6H2O
