No i didn't :!:
Its in 'Cambridge O Level' forum and is titled 'Chemistry' so i know its '5070 - Chemistry'.
Like my second post, 'Which Paper?'
Paper 1, Paper 2 or what?
Why don't you paste a link here?
And which question?
like Q.2b(ii) etc
B9, B10 etc doesn't makes sense :!:
B7(a):
Oxidation state of Nitrogen changes from 0 to 3.
B7(b):
2NO3ˉ + 12H
+ 10eˉ → N2 + 6H2O
B7(c)(i):
Nitrogen can be taken from air and Hydrogen can be taken from Water.
B7(c)(ii):
400ºC temperature and iron catalyst.
B7(d):
NH4NO3 : 100 x (28/80) = 35%
(NH4)2HPO4 : 100 x (28/132) = 21.2%
So NH4NO3 clearly contains greater percentage of nitrogen by mass.