Qualification > Sciences
ALL CIE CHEMISTRY DOUBTS HERE !!
Amelia:
--- Quote from: EMO123 on February 21, 2011, 06:08:03 pm ---What are the Friedel-Crafts Catalyst?
--- End quote ---
They are the catalysts used in the Friedel-Crafts reactions.
Here are examples of the reactions - http://www.chemguide.co.uk/organicprops/arenes/fc.html
--- Quote from: mixed on February 21, 2011, 04:45:50 pm ---Thanks tons!
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Welcome:)
EMO123:
--- Quote from: Amelia on February 21, 2011, 06:35:50 pm ---They are the catalysts used in the Friedel-Crafts reactions.
Here are examples of the reactions - http://www.chemguide.co.uk/organicprops/arenes/fc.html
Welcome:)
--- End quote ---
thanxxs
TheLonelyIsland:
Hi, can someone PLZ help me with this question? I'm so stupid, it's really easy, but I keep getting the wrong answer :o :
"Which of these samples of gas contains the same number of atoms as 1g of hydrogen
(Mr : H2, 2)?
A 22 g of carbon dioxide (Mr: CO2, 44)
B 8 g of methane (Mr: CH4, 16)
C 20 g of neon (Mr: Ne, 20)
D 8 g of ozone (Mr: O3, 48) "
According to ms, the correct answer is C...How do you do it correctly? Arghh, so frustrating when you don't know, lol...
Thx in advance,
Take care
Deadly_king:
--- Quote from: TheLonelyIsland on March 07, 2011, 01:37:04 am ---Hi, can someone PLZ help me with this question? I'm so stupid, it's really easy, but I keep getting the wrong answer :o :
"Which of these samples of gas contains the same number of atoms as 1g of hydrogen
(Mr : H2, 2)?
A 22 g of carbon dioxide (Mr: CO2, 44)
B 8 g of methane (Mr: CH4, 16)
C 20 g of neon (Mr: Ne, 20)
D 8 g of ozone (Mr: O3, 48) "
According to ms, the correct answer is C...How do you do it correctly? Arghh, so frustrating when you don't know, lol...
Thx in advance,
Take care
--- End quote ---
Hmm..........it's not very difficult. ;)
The most important thing that you need to know is that 1 mole of any substance contains 6.02 x 1024 number of atoms. ;)
So you've been asked to find a sample with the same number of atoms as 1g of hydrogen. 1 gram of Hydrogen as you should be knowing is equal to 1 mole of hydrogen (Ar of H = 1).
In other words, now you need to look for a sample representing one mole. You can use the following formula to do do so.
No of moles = Mass / Mr
A ----> No of moles = 22/44 =0.5
B ----> No of moles = 8/16 = 0.5
C ----> No of moles = 20/20 = 1
D ----> No of moles = 8/48 = 0.17
You'll note that only C offers this possibility. ;)
Hope it helps :)
TheLonelyIsland:
thx a lot, i knew it was something really easy... What confused me was that Mr H2=2... Dumb, I know! Thx, again!
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