Qualification > Sciences
CHEM AND BIO HELP AND TIPS HERE
6394:
m/j 2005
chem ppr 3
q4 d
how do u noe x=2
Thanks
sarasa:
--- Quote from: ahmediiii on June 05, 2010, 01:07:45 pm ---umm... i already know this ,see i was kinda wondering why this happens... sorry
--- End quote ---
I think i can explain y but on one condition my doubt gets answered about da labelled diagram, ok?
U know dat any reversible reaction at da state of equilibrium means dat neither sides is prevailing so if it goes in one direction, it undergoes da reverse reaction so it continues to go like this until u change da conditions which could be increasing da pressure as da first example, so think of a piston being pushed, what happens to volume of air, it decreases, rite? so this is da exact same thing on increasing pressure, volume decreases so da side of da rection with lower volume (remember this only for gas) would be favoured, u can know that by looking at da no. of moles...
NOW, da second example is increasing da concentration, if u add more of A in this reaction, wat would happen? A+B=>C+D
There is more of A nd this disturbs da equilibrium in order to return to it, the reaction speeds up towards the RHS in order to remove da extra A added
LAST is temperature, usually either da forward or da backward would be exothermic(gives off heat) nd naturally da other would be endo (takes in heat)
so when u raise da temp., equilibrium is again disturbed so to decrease it da endo is favoured why because it takes in heat so will eventually lower da temp. Got it???
JD46:
MJ04 Q4 how do i know what salt to use, what cant it be a zinc oxide or hydroxide for preparing an insolubles salt?
$H00t!N& $t@r:
--- Quote from: furqan on June 05, 2010, 12:47:12 pm ---no not that way
it ws sumthin like
above 'this' metle
only elctrolysis
and so on so forth
cud u tell me bout that
like explain
plz?
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Method of Extraction
The method used depends on the reactivity of the metal
Very reactive metals
Electrolysis (Decomposing metal compound with electricity)
Potassium
Sodium
Calcium
Magnesium
Aluminium
Moderately reactive metals
Heating metal oxide with coke
Zinc
Iron
Lead
Low Reactivity metals
Heating metal compounds in air
Copper
Silver
rameeziiii:
--- Quote from: Jaw@!r!a on June 05, 2010, 01:21:24 pm ---m/j 2005
chem ppr 3
q4 d
how do u noe x=2
Thanks
--- End quote ---
looking it up
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