Author Topic: Chemistry Help HERE ONLY !!  (Read 106053 times)

Offline zubair_slipknot

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Re: Chemistry Help HERE ONLY !!
« Reply #105 on: May 27, 2009, 09:03:22 am »
yes its absolutely like this

by the way how is the production of iron in the blast furnace
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Offline Bessy

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Re: Chemistry 2009!!! Paper 3 prep.....
« Reply #106 on: May 27, 2009, 09:38:25 am »
Hey, does anyone know what colour change occurs when potassium iodide is reduced??? Its in the syllabus, you gotta know this!!!!
  umm  there is no color for iodine ion i am sure
 when iodine become atom (that with no overall charge)  its colour is yellow

Offline lana

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Re: Chemistry Help HERE ONLY !!
« Reply #107 on: May 27, 2009, 09:58:47 am »
hey lana

it goes like this


3 mols of co2 give 15 cm3
so what will 5 mols of oxygen give?
its simply cross multiplication

no. of mols                 volume
     3                            15
     5                              ?

so (5 x 15)
   ---------= 25cm3
        3

then to get the volume for propanol (C3H8) which is 1 mol ,do the same

no. of mols                   volume
      3                              15
      1                                ?
 
so    (1 x 15)
     ----------  = 5cm3
           3

so the answer is for oxygen=25     and   for  propanol=5

hope u understand, any confusion or difficluties or help, plz do ask me



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Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #108 on: May 27, 2009, 10:03:57 am »
ure welcome, dnt forget to +rep me (god i hate sayin this, makes me fell im selfish)
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Offline MaNa

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Re: Chemistry Help HERE ONLY !!
« Reply #109 on: May 27, 2009, 10:54:08 am »
yes its absolutely like this

by the way how is the production of iron in the blast furnace
iron production
Raw material Iron ore coke lime stone
temperature 1900*C
1) C+O2= CO2
2) Co2+C=2CO
the CO2 rises n reacts with more C to orm C0
3) Feo3 +2co= 2fe +3co2
the Co reduced the iorn ore at the top of the furnace to molten iron metal (pig iron) which fallls to the bottom of the furnace n Co2 escapes freom the top as a waste gas
4) limestoen is present to help remove impruties .the main impuritty is sand (silicon oxide) inside the furnace the limestone  decompses tof orm Cao  n co2
CaCo3=CaO +co2
5) the co2 whch is produces reacts with the hot coke yo produce more Co but the lime combines with the sand impurity to form a molten slag alled Calcium siliate
CaO+ SiO2=CaSiO3
the slag bcuz its molten runs to the bottom of the furnace asd its lighter then molten iron thus it floats on the surface n can be tapped off
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Offline lana

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Re: Chemistry Help HERE ONLY !!
« Reply #110 on: May 27, 2009, 12:56:48 pm »
if propanol and propanoic acid react they give an ester can anybody please name that ester and draw it's structural formula...
thanks
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Offline MaNa

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Re: Chemistry Help HERE ONLY !!
« Reply #111 on: May 27, 2009, 01:35:20 pm »
if propanol and propanoic acid react they give an ester can anybody please name that ester and draw it's structural formula...
thanks

C3H7OH+C2H5COOH=   C2H5COOC3H7 +H2O
name:proylpropenoate ( not sure)
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Offline lana

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Re: Chemistry Help HERE ONLY !!
« Reply #112 on: May 27, 2009, 01:39:12 pm »
thank you =]
+rep
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Offline MaNa

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Re: Chemistry Help HERE ONLY !!
« Reply #113 on: May 27, 2009, 01:42:42 pm »
CORRECTION
C2H5COOC3H7
n thx for + rep
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nid404

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Re: Chemistry Help HERE ONLY !!
« Reply #114 on: May 27, 2009, 03:26:41 pm »
here propyl propanoate     

Offline Naruto

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Re: Chemistry 2009!!! Paper 3 prep.....
« Reply #115 on: May 27, 2009, 03:44:57 pm »
well Bessy i think that potassium is yellow not iodine...
and ioden is purple/black that wat i think...
and +rep if i m correct :)

Offline lana

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Re: Chemistry Help HERE ONLY !!
« Reply #116 on: May 27, 2009, 04:30:44 pm »
thank you that really helped =]
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Offline Igcseboy

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Re: Chemistry 2009!!! Paper 3 prep.....
« Reply #117 on: May 27, 2009, 05:47:20 pm »
All moles formula plzzz attach here anyone thnxzzzzzzz  :-X

Offline Shogun

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Re: Chemistry 2009!!! Paper 3 prep.....
« Reply #118 on: May 27, 2009, 05:54:05 pm »
to find the number of mole with mass and Mr and Ar.
Moles=mass/Ar or Mr

to find number moles with volume
moles= volume in dm3 / 24

if the volume was in cm3 then devide it by 10000. (to do any calculations with volume in it, the volume must be in dm3)
volume in dm3= volume in cm3/1000

to find number of moles interms of volume in dm3 and concentration (unit=(v/dm3))
moles= volume in dm3 x concentration

thts all with the moles. hope it helped
« Last Edit: May 27, 2009, 05:55:45 pm by Shogun »
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Offline MaNa

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Re: Chemistry Help HERE ONLY !!
« Reply #119 on: May 27, 2009, 07:20:38 pm »
Can someone explain me Q5 (p3 M/J 08)
its equlibirum i
i need to understand
I POSTION OF EQULIBRUM n WHAT HAPPENEDS  ??? ???
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