Inorganic Chemistry And The Periodic Table Flashcards
Group 2 + oxygen
General equation
Solid white oxide
2M(s) +O2(g)—-> 2MO(s)
Group 2 + chlorine
General equation
Solid white chlorides
M(s) + Cl2(g)——-> MCl2(s)
Group 2 + water
General equation
Metal hydroxide + hydrogen
M(s) + 2H2O(l) —-> M(OH)2 (aq) + H2(g)
Group 2 oxide + water
General equation
Hydroxides
MO(s) + H2O(l)—-> M(OH)2 (aq)
Group 2 oxide+ dilute acid
General equation
Salt+water
MO(s)+2HCl(aq)—-> MCl2(aq)+H2O(l)
Group 2 hydroxide + dilute acid
General equation
M(OH)2(aq)+2HCl(aq)—-> MCl2(aq)+2H2O(l)
Solubility trend group 2 hydroxides
Increases down the group
Solutions more strongly alkaline
Solubility trend group 2 sulfates
Decreases down the group
Trend in thermal stability down the group for G2 carbonates and nitrates
Increases
Polarising power of the cation decreases down the group as the ionic radius increases and so more shielding (lower charge density)
Less distortion of carbonate/ nitrate anion
Weakens the CO/ NO bond less
Thermal stability of G2 vsG1 nitrates/ carbonates
G2 carbonates/ nitrates are less thermally stable
The greater the charge on the cation, the greater the distortion and the less stable to anion becomes
2+ vs 1+
Thermal decomposition of G1 carbonates
Thermally stable (until higher temperatures)
Exception: Li2CO3 which decomposes to Li2O and CO2
Thermal decomposition of G2 carbonates
Form oxide and carbon dioxide
MCO3 (s)—-> MO(s) + CO2 (g)
Thermal decomposition of G1 nitrates
Forms nitrite and oxygen
2MNO3(s)——>2MNO2(s)+O2(g)
Exception:
LiNO3 which decomposes to form Li2O, NO2, O2
thermal decomposition of G2 nitrates
Forms oxide, nitrogen dioxide, oxygen
2M(NO2)2(s)——>2MO(s)+4NO2(g)+O2(g)
Testing the thermal stability of nitrates
How long it takes for a certain amount of oxygen to be produced (enough to relight a glowing splint)
How long it takes for an amount of brown gas (NO2) to be produced (in a fume cupboard)