period 3 elements done io yr2 Flashcards
why is Na more reactive than Mg
Because Na only has to lose 1 electron to react whereas Mg has to lose 2. so more energy is needed to lose them.
how does Na react with cold water
Equation?
2Na(s) + 2H2O(g)===== 2NaOH(aq) + H2(g)
observation= molten ball and fizzing
vigorous
how does Mg react with cold water
Equation?
Mg(S) + 2H2O(cold water)===== Mg(OH)2(aq) + H2(g)
Slow with water fast with steam
Thin coating froms of Mgoh on the metal.
how does Mg react with Steam?
Mg(S) + H2O(steam(G))===== MgO + H2
what is S normally oxidised to
S + O2 ==== SO2
How can you oxidise S to SO3
add a vanadium catalyst to SO2 reaction
How quick is the reaction with air(oxygen) in the period 3 oxides
Na, Mg(vigorous)
P(spontaneously combusts)
S(burns readily)
Al, Si (slow)
which of the metal oxides have a covalent structure?
SiO4(macro)
P4O10, SO2(simple)
which of the metal oxides have an ionic structure?
Na2O
MgO
Al2O3
Why does MgO have higher Mp than Na2O
because more charged ion
higher forces of attraction
Why does Al2O3 have a lower Mp than Na2O
Al3+ ion distorts oxygens electron cloud to make it slightly covalent
Which oxides are acidic
ionic oxides
what is the reaction of the ionic oxides in water
Na2O(s) + H2O===== 2NaOH(aq)
MgO(s) + H2O===== Mg(OH)2(aq)
why does MgO form a less alkaline solution than Na2O
because NaOH is more soluble in water.
NaOH is the product formed
Whic Oxides are acidic
covalent oxides are acidic
reactions of covalent oxides with water
P4O10 + H2O ==== H3PO4
SO2 + H2O ==== H2SO2
SO3 + H2O ==== H3SO3
why is SiO2 classed as acidic even though its insoluble in water?
Because it reacts with bases to form a salt
why is aluminium amphoteric. equations?
Partially ionic and partially covalent and insoluble. so both. it reacts with both acids and bases to make salts.
Al2O3 + 3H2SO4 ==== Al2(SO4)3 + 3H2O
Al2O3 + 2NaOH + 3H2O ===== 2NaAl(OH)4
equations for acidic(covalent) oxides neutralising bases
SiO2 + 2NaOH ===== SiNaO3 + H2o
P4O10 + 12NaOH ====== 4Na3PO4 + 6H2O
SO2 + 2NaOH ===== Na2SO3 + H2O
SO3 + 2NaOH ===== Na2SO4 + H2O
equations for basic(ionic) oxides neutralising bases
Na2O + 2HCl ==== 2NaCl + H2O
MgO + H2SO4 ==== MgSO4 + H2O
