Inorganic Unit 2.2: Group 2 Flashcards
what is the trend in atomic radius down group 2 & why?
atomic radius increases down group
bc there are more shells so e-s further from nucleus
what is the trend in 1st ionisation energy down group 2 & why?
1IE decreases down group
bc atomic radius increases
shielding increases
so weaker attraction b/w outer shell e-s & nucleus
what is the trend in melting point down group 2 & why?
mp generally decreases down group
bc ions are bigger
so weaker attraction b/w +ve ions & delocalised e-s
what are the observations for reaction of Mg & water?
no reaction/v slow with cold water
with steam: burns w bright white flame to form white powder
what are the observations for reaction of Ca & water?
fizzes
white solid forms
what are the observations for reaction of Sr & water?
fizzes
colourless solution
what are the observations for reaction of Ba & water?
fizzes
colourless solution
equations for group 2 metals reacting with water
see notes booklet
what is the trend in reactivity down group 2 & why?
reactivity increases down the group
bc
when metals react, they lose their 2 outer shell e-s
down the group, atomic radius increases, shielding increases
so weaker attraction b/w nucleus & outer shell e- so outer shell e-s are more easily lost
what is the use of magnesium hydroxide?
indigestion relief
what is the use of calcium hydroxide?
used in agriculture to neutralise acidic soil
what is the use of CaO or CaCO3?
to remove SO2 from flue gases
what is the use of barium sulfate?
‘barium meal’
X-rays of digestive tract bc insoluble so not absorbed
what is barium chloride used for & why?
why is it acidified?
to test for sulfate ions bc BaSO4 precipitate is insoluble so it is visible
to remove carbonate ions
what is the trend in solubilities of group 2 hydroxides?
solubility of hydroxides increases down the group
Mg(OH)2 is sparingly soluble
