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

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: AN10 on June 03, 2010, 03:37:19 pm

Title: chem doubt
Post by: AN10 on June 03, 2010, 03:37:19 pm

M/J 09 chem p1 mcq no. 11...why is the ans C....why it cannot be D ( i get it A and B are not possible but am confused bw C and D)

Title: Re: chem doubt
Post by: nid404 on June 03, 2010, 03:52:31 pm

You straight away eliminate A and B as they produce no unreactive gas (N2)
The reaction is as such

3Ba(NO3)2 + heat ? 3BaO + 6NO2 + 3O2

10Al + 3BaO + 6NO2 + 3O2---> Al2O3 + 3BaO+ 3N2

Title: Re: chem doubt
Post by: toleen on June 03, 2010, 05:02:19 pm

I NEED SITES FOR DOWNLOADING PRACTUCE SHEETS OTHER THAN THE PAST PAPERS

Title: Re: chem doubt
Post by: toleen on June 03, 2010, 06:10:49 pm

ANY 1 hELLO

Title: Re: chem doubt
Post by: nid404 on June 03, 2010, 06:23:02 pm

You can try past papers of other boards  :-\

or try this link ...it has practice sheets. http://www.a-levelchemistry.co.uk/AQA%20AS%20Chemistry/new%20AS%20Chemistry%20home.htm

Title: Re: chem doubt
Post by: leebux101 on June 03, 2010, 07:20:06 pm

can someone plz tell me Q21 from MJ 02
plz!

Title: Re: chem doubt
Post by: leebux101 on June 03, 2010, 07:42:34 pm

can u also help with Q5 from ON 02

Title: Re: chem doubt
Post by: toleen on June 03, 2010, 07:43:48 pm

THANKS nid404  :)