Chapter 8 Flashcards
group 2 known as
alkaline earth metals, do not occur in elemental form
group 2 metals redox
reducing agents, they reduce another species
group 2 trend in periodic table
reactivity increases down the group
why does group 2 reactivity increase down the group
loses 2 outer shell electrons to form 2+ ions
atomic radius increases=shielding increases=attraction decreases= easier to lose electrons= higher reactivity
group 2 reactions with oxygen
metal+ oxygen->metal oxide
group 2 reactions with water
metal+ water-> metal hydroxide+ hydrogen
group 2 compound reactions(metal oxides)
metal oxide+water->metal hydroxide
group 2 hydroxides reactions
metal hydroxide+acid-> metal/salt+ water
uses of calcium hydroxide
added as lime to increase ph of acidic soils
group 2 carbonate reactions
metal carbonate+ acid-> metal+ water+ co2
group 7
halogens
antacids for acid indigestion
milk of magnesia/magnesium hydroxide
indigestion tablets/calcium carbonate
trend in halogens
down a group
boiling point increases
stronger london forces= more energy needed to overcome the IM forces
disproportionation
a redox reaction in which the same element is oxidised and reduced
example: chlorine and water disprop
cl2+h2o->hclo+hcl
chlorine is oxidised and reduced
example: chlorine and sodium hydroxide
cl2+2naoh->NaClO+NaCl+h2o
chlorine is oxidised and reduced
chlorine benefits and risks
ensures water is safe to drink, kills bacteria
X extremely toxic(small=respiratory irritant, large= fatal)
in water- reactions to form chlorinated hydrocarbons=
carcinogenic
