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

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: AN10 on March 18, 2010, 05:13:53 pm

Title: chem mcq
Post by: AN10 on March 18, 2010, 05:13:53 pm

someone plz explain to me MCQ 19 and 21 of oct/nov 09 p11

Title: Re: chem mcq
Post by: nid404 on March 18, 2010, 06:06:22 pm

upload the paper plz...my file's corrupted :(

Title: Re: chem mcq
Post by: AN10 on March 18, 2010, 07:36:16 pm

here is da paper

Title: Re: chem mcq
Post by: nid404 on March 19, 2010, 04:28:31 am

Q19)
 ammonium is NH_{4 +}
so cyanate will have 1- charge...B is ruled out
cyanide is CN^-
cyanate will be oxidised cyanide......hence CNO^-
A

21)

Total no of double bonds
3 in the cyclohexane ring
1 in the aldehyde (C=O)
1 is the alkene C=C between C11 and C12

so total of 5

cis isomer has the higher groups(R) on the same side.

Hence A