IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: ashish on November 04, 2010, 04:04:25 pm

Title: mcq chemistry
Post by: ashish on November 04, 2010, 04:04:25 pm
ok one MCQ question

In 1982, LOrd Rayleigh made 'atmospheric nitrogen' by removing oxygen from atmosphere .he found the density of this nitrogen to be 1.2572gdm-3 at s.t.p . Chemically pure nitrogen has a density of 1.2505gdm-3.

which gas was present in 'atmospheric nitrogen' to create this discrepancy?

A argon
B helium
C methane
D neon
Title: Re: mcq chemistry
Post by: Deadly_king on November 05, 2010, 05:09:57 am
Quote from: ashish on November 04, 2010, 04:04:25 pm
ok one MCQ question

In 1982, LOrd Rayleigh made 'atmospheric nitrogen' by removing oxygen from atmosphere .he found the density of this nitrogen to be 1.2572gdm-3 at s.t.p . Chemically pure nitrogen has a density of 1.2505gdm-3.

which gas was present in 'atmospheric nitrogen' to create this discrepancy?

A argon
B helium
C methane
D neon

I guess it should be Argon since it is the most abundant inert gas in atmospheric air.

If you try to calculate the Ar of the gas present, it does not lead to any of the answers. :-\
Title: Re: mcq chemistry
Post by: ashish on November 05, 2010, 08:18:20 am
ah ok thank you !
Title: Re: mcq chemistry
Post by: Deadly_king on November 05, 2010, 08:32:59 am
Quote from: ashish on November 05, 2010, 08:18:20 am
ah ok thank you !

Anytime br0 ;)

But am not 100% confident.

If possible contact your teacher for confirmation. :)
Title: Re: mcq chemistry
Post by: hell0 on November 07, 2010, 02:48:42 am
Oh wheww
I did a double bond for the C2O question

Paper 32 ppl: How did you find the organic part of the paper?
Title: Re: mcq chemistry
Post by: Deadly_king on November 07, 2010, 05:08:19 am
Quote from: hell0 on November 07, 2010, 02:48:42 am
Oh wheww
I did a double bond for the C2O question

Paper 32 ppl: How did you find the organic part of the paper?


Yeah C20 has 2 double bond.

C=C=O

I already explained it here (https://studentforums.biz/sciences-149/chemistry-paper-22-3rd-nov/).(on the 1st page)

P32 was pretty easy ;)

How did you find your paper?