Inorganic Chemistry Flashcards
Down group 2 IE does what and explain why relating to how reactions occur in metals
Shielding increases
Nuclear charge increases but is outweighed
Nuclear attraction decreases
Atomic radi increases
Reactivity increases as they react by losing electrons.
Group 2 metal + 1/2O2(g)->
Also give state symbol
MO(s)
Group 2 M (s) + Cl2 (g) ->
Add state symbol
MCl2 (s)
Group 2 metal + 2H2O (l) ->
Add state symbols
M(OH)2 (aq) + H2 (g)
Reactions of group 2 metal with oxides:
MO (s) + H20 (l) ->
MO (s) + 2HCl (aq) ->
Add state symbols
M(OH)W (aq)
MCl2 (aq) + H20 (l)
Group 2 metal with hydroxide/ base:
M(OH)2 (s) + 2HCl (aq) ->
Add state symbols
MCl2 (aq) + 2H2O (l)
Solubility trends group 2 metals acronym, explain, examples
HIS DOG
hydroxides increase, sulfatos decrease, down group
Ba(OH)2 is soluble
BaSO4 is insoluble
Explain the Thermal decomposition trend down group two
Gets harder to decompose down the group hence more thermal energy is needed, the cation gets larger hence is less polarising hence less weakening in the bonds of an anion.
Li and group 2 nitrates thermal decomposition reactions examples :
2LiNO3 (s) -> (heat on top of arrow)
Ca(NO3)2 (s) -> (heat on top of arrow)
Add state symbols
Li2O (s) + 2NO2 (g) + 1/2 O2 (g)
CaO + 2NO2 (g) + 1/2O2(g)
NO2 (g) = brown fumes
Feast of group one nitrate thermal decomposition reactions:
MNO3 (s) -> (heat on top of arrow)
Add state symbols
MNO2 s) + 1/2O2 (g)
Metal NO2 is not brown fumes
Li and group 2 carbonates thermal decomposition reactions:
Li2CO3 (s) -> (heat on top of arrow)
CaCO3 (s) -> (heat on top of arrow)
Add state symbols
How do we test for CO2?
Li2O (s) + CO2 (g)
CaO (s) + CO2 (g)
Limewater turns milky
Reactions of group one carbonates thermal decomposition reactions? And explain why?
Do not undergo because the cations are too lowly charges/ have too large a radius to polarise the anion as much as lithium or calcium ions
Flame test procedure
Clean a nichrome/ platinum wire loop by dipping in HCl
Put in fire to sterilise
Dip in sample
Put in flame and observe colour change
Flame test colours of: Li + Ma+ K+ Rb+ Cs+
Red Yellow Lilac Red/purple Blue/violet
Flame test colours of: Be2+ Msg 2+ Ca2+ Sr2+ Ba2+
No colour No colour Brick red Crimson red Apple green
Explanation for why colours are seen when reacting group one and two metals in flame tests. Also relate to Be2+ and Mg2+.
The electrons absorb energy and exalted from their ground state level to a higher energy state and when they fall back down again, energy of a specific frequency is releases which is observed as a colour.
Be2+ and Mg2+ release a wave of frequency not in visible light spectrum.
Trend in melting point down group seven halogens?
Decreases down the group