IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: Zain-Xa on June 09, 2009, 04:11:01 pm
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guyz in p1 o/n 2006 q19
could any1 explain the question ????
the answer in the markscheme is B
Thanks in adv. :)
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crystallisation will obtain the crystals of the compunds but there will still be a little liquid mixed
therefore u have to filter it
:)
nid404 can add on to that..nid u dere??
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guyz in p1 o/n 2006 q19
could any1 explain the question ????
the answer in the markscheme is B
Thanks in adv. :)
It's B because the barium sulphate is insoluble and needs to be filtered, whereas barium chloride is soluble and needs to be obtained by crystallisation
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Thanks guyz +rep :)
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nid +rep to u too
50!!! (second time)
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nid +rep to u too
50!!! (second time)
no use.....now i really can't help it but say i don't care...it keeps falling
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heey again does any1 know any gd sites 2 practice chem multiple chice question ???
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heey again does any1 know any gd sites 2 practice chem multiple chice question ???
guyz answer plssss :(
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Yh Past Papers :D
IF your country is Supporting IGCSE as well as Egypt is :p You should find Bookshops for IGCSE Like her in Egypt we have Loads and all are official
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need help agai n !!?
q 3 in m/j 07 i dnt get it ???
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This is a thermometer...He is askin gyou what could be the temprature...The point on the left might be 70/80/100 and the point on the left can be 80/90/110 right? So you count to see which is the more reliable answer so it's 75.5 as the point on the right will be 70 and on the left 80
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ohhkk i sort of get thnk u :)
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Try to do it, did you get it?
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ya i did do it but umm hw do u know wether its 105.5 or 85.5 ???
the rest i gt !
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ya i did do it but umm hw do u know wether its 105.5 or 85.5 ???
the rest i gt !
Boiling point is less than that of water. Water boils at 100, so the reading is surely less than 100.
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ya i did do it but umm hw do u know wether its 105.5 or 85.5 ???
the rest i gt !
the boiling point of the liquid is lesser than that of water...so it has to be less than 100
plz read the questions carefully...this is how we tend to make mistakes
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ya i did do it but umm hw do u know wether its 105.5 or 85.5 ???
the rest i gt !
the boiling point of the liquid is lesser than that of water...so it has to be less than 100
plz read the questions carefully...this is how we tend to make mistakes
ohk ya nd i know i make mistakes b/c i dnt read properly :-[
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can any 1 plz post chemistry past papers from 93 _ 95 and their mark scheme.
thanx in advance
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which salts are soluble in acids and which salts react with acids? ???
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cn anyone pls help me?
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which salts are soluble in acids and which salts react with acids? ???
Well, for example:
HCl will be able to displace HNO3 from a nitrate salt, but HNO3 will not be able to displace the stronger HCl from a chloride salt.
another example,
HNO3 is more reactive than sulphuric acid, so HNO3 will displace a sulphate salt
Also...
CuCO3 (contains carbonic acid which is a very weak acid) + H2SO4 --> CuSO4 + H2O + CO2
It depends on the strong acidity of the acids reacted
About which salts are soluble inside, calm down that is not necessary in IGCSE i guess :P~
just learn the basic insoluble and soluble salts ;D
good luck