Author Topic: Chemistry Help HERE ONLY !!  (Read 107352 times)

Offline unknown 101

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Re: Chemistry Help HERE ONLY !!
« Reply #270 on: May 29, 2009, 01:11:50 pm »
petroleum fractions:

Gas: seperated into methane, ethenane, propane, and butane- all fuels
Petrol: used for car fuel
Naptha: used for making chemicals
Kerosene (parrafin): used as fuel for jets and oil stoves and also used as detergents
Diesel oil: fuel for central heating, for diesel engines
Lubricating oil: oil for cars and other machines
Fuel oil: fuel for power stations and ships
Parrafin wax: used for making candles. wax-paper, waterproofing and greasing
Bitumen: used as pitch for roads and roofing tar
« Last Edit: May 29, 2009, 01:14:36 pm by LilWayne »

Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #271 on: May 29, 2009, 01:12:51 pm »
im gonna give u ther frations in order and thier uses

1st is refinary gas, which can be used as fuel, or cooking
2nd is gasoline, which is used in cars as its petrol
3rd is naptha which is used to make chemicals
4rth is kerosene/paraffin, which can be used as a fuel for jet engines
5th is diesel oil/gas oil, which can be used as a fuel in diesel engines (eg: trucks)
6th is fuel oil.used as fuel for ships or home heating system
7th,is lubricating oil wich can be used to surface road (eg bitumen) ,it is ver heavy, it can also be used to make waxes...

hope this helped
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Offline emi

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Re: Chemistry Help HERE ONLY !!
« Reply #272 on: May 29, 2009, 01:34:34 pm »
can some one post about contact process and how sulphuric acid is made ?

and in moles stuff can some one post the formula;s required , and if you have any tips or easy way to work out the answers ? and solve

1- M/j 2005 paper 3 Q5 d)
2- O/N 2005 Q6  ( all parts )


thanks ALOT, you guys are Awesome  specially shogun and lilWayne  ( just dnt ovr react if ppl had diff. opinion about your fav rapper ;) )

thanks again
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Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #273 on: May 29, 2009, 01:39:02 pm »
lol emi, i dont like rap, i only listen to metal or punk rock
one who masters both the pen and paper is indeed a true warrior.

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Offline emi

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Re: Chemistry Help HERE ONLY !!
« Reply #274 on: May 29, 2009, 01:40:51 pm »
i meant lilwayne not you ,, i know your taste ;)

rock ftw!
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Offline ZeroZero82

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Re: Chemistry Help HERE ONLY !!
« Reply #275 on: May 29, 2009, 01:48:19 pm »
can some one post about contact process and how sulphuric acid is made ?

and in moles stuff can some one post the formula;s required , and if you have any tips or easy way to work out the answers ? and solve

1- M/j 2005 paper 3 Q5 d)
2- O/N 2005 Q6  ( all parts )


thanks ALOT, you guys are Awesome  specially shogun and lilWayne  ( just dnt ovr react if ppl had diff. opinion about your fav rapper ;) )

thanks again

Obtain O2 or N2 from air by cooling the air under pressure lo liquify it. Then fractional distillation of liquid air.
Burn S in pure O2  ( S + O2 ---> SO2)
convert SO2 to 2SO3 (2SO2 + O2 <---> 2SO3 conditions:-temp. 450C, catalyst:V2O5,pressure:2atm)
Convert SO3 to Oleum(H2S2O7) (SO3 + H2SO4 --->H2S2O7)
then H2S2O7 + H2O ---> 2H2SO4 (concentrated)
;D
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Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #276 on: May 29, 2009, 01:54:06 pm »
oh alrighty then, then im gonna start with the contact process first..

1)first,sulphur is allowed to react with oxygen to form sulphur dioxied(its an oxidation reaction as oxygen is taken)
2)then this sulphur dioxide is allowed to react with oxugen again to make sulphur trioxide (SO3). this reaction has some rquirements which are : catalyst: vanadium pentoxide or vanadium (v) oxide(V2O5),temperature : 450oC, and its at atmospheric preassure (but is unspecified on what ammount of atmospheric preassure).
3) sulphuric acid can esily made by just reacting water with sulphur trioxide directly, however this reaction is vilent and produces thick mist like smoke tht can cause u to choke, so to avoid this problem, the sulphur trioxide is dissolved in some sulphuric acid (labratory prepared one) to give oleum (H2S2O7)
4) then correct amount of water is added to this oleum to produce sulphuric acid of the required concentration.

and thts all with the contact process, hope this helped, then ill try to answer the moles stuff later, but the required formulas needed for moles are here:
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

 :D ;D
one who masters both the pen and paper is indeed a true warrior.

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Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #277 on: May 29, 2009, 01:59:47 pm »
hmm thier aint no section d in question 5 of paper 3 may/june,
did u mean q4'd'
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Offline aquarian93

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Re: Chemistry Help HERE ONLY !!
« Reply #278 on: May 29, 2009, 02:04:16 pm »
hey u guys
wat do we need to noe abt "soaps" in organic chem. i dont understand that part
thannkss

can sum1 pls clear my doubt on this?

all u need to know about soap is how to make one. which is by reacting fat (oil) with an alkali (like sodium hydoroxide) , the chemical name for soap is sodium sterate.

and about kerosene (the correct spelling,lol) is used as fuel for jet plane with it comes paraffin where both are in the 4rth fraction.

okay. thanks =)

and how abt "what does the alkaline hydrolysis of vegetable oil produce"

Offline unknown 101

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Re: Chemistry Help HERE ONLY !!
« Reply #279 on: May 29, 2009, 02:04:56 pm »
can some one post about contact process and how sulphuric acid is made ?

and in moles stuff can some one post the formula;s required , and if you have any tips or easy way to work out the answers ? and solve

1- M/j 2005 paper 3 Q5 d)
2- O/N 2005 Q6  ( all parts )


thanks ALOT, you guys are Awesome  specially shogun and lilWayne  ( just dnt ovr react if ppl had diff. opinion about your fav rapper ;) )

thanks again

nov05
Q6)
a)i)number of moles of NiCO3 reacted = 0.08 mol (1:1 ratio with the sulphuric acid)
Mass of nickel carbonate reacted = mass=moles x mr --- 0.08 x 119 = 9.52 g
mass of unreacted nickel carbonate =  12.0 - 9,52 = 2.48

ii)maximum number of moles = 281 x 0.08 = 22.48
percentage yeild = 10.4/22.28  x 100 = 46.3%

b)i) by titration ( acid + alkali) and explain the process

b)ii) heat calcium and flourine together
or use precpitation method
eg. calcium nitrate + pottasium flouride ----> patasium nitrate + calcium flouride

Offline emi

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Re: Chemistry Help HERE ONLY !!
« Reply #280 on: May 29, 2009, 02:22:16 pm »
oh shogun there is Q5 section d  in Q4 there is no section d
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Offline unknown 101

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Re: Chemistry Help HERE ONLY !!
« Reply #281 on: May 29, 2009, 02:24:55 pm »
oh shogun there is Q5 section d  in Q4 there is no section d

im srry emi but there is no Q5 section D but there is Q4 section D,, how about write the question??

Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #282 on: May 29, 2009, 02:27:10 pm »
hey emi, to do q4 in m/j 2005

4di) mass/ Mr so 79.1/136
u get=0.58 moles

4dii) mass/ Mr so 20.9/18
u get= 1.16

4diii) here its like common sense or some thin, cuz u have to devide the number of moles of water by the number of moles of calcium sulphate.. so 1.16/0.58
u get x=2

then for the oct/nov 2005 q6
the first thing is like wat lil wayne told u
one who masters both the pen and paper is indeed a true warrior.

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Offline emi

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Re: Chemistry Help HERE ONLY !!
« Reply #283 on: May 29, 2009, 02:27:32 pm »
lilwayne thanks but  i could have looked up the answers in MS too  :-X .. i wanna  know how to do it like an explanation would be more good

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Offline Shogun

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Re: Chemistry Help HERE ONLY !!
« Reply #284 on: May 29, 2009, 02:29:56 pm »
alright then ill xplain it to u...
one who masters both the pen and paper is indeed a true warrior.

\m/metal head\m/