Chemistry May/June 2010

[abcde]

AOA!
I don't understand question B8 (c) (ii) of this paper: http://www.xtremepapers.me/CIE/Cambridg ... _qp_21.pdf
Kindly help asap! :?

 

[scouserlfc]

Its pretty easy just use the instructions they give

the compound on decomposing forms steam and a gas X right ?

NH4NO3 > 2H2O + N2O

N2O is called nitrous oxide commonly known as laughing gas.Was this all u required u can see the question only provides the hint.

The salt decomposes when heated gently to form steam and a colourless gas X.
so make a balanced equation and ull be able to get what X is.
Hope u get it and i wrote correct

 

[abcde]

How do you know in the first place that nitrous oxide is formed? Normally,when nitrates undergo thermal decomposition, a metal oxide, nitrogen dioxide and oxygen are formed! :S

 

[leosco1995]

That may be normally, but in this specific question it is clearly stated that a gas X and steam are formed so you have to follow the instructions they give. If you make a balanced chemical equation (like scouserlfc did), then you will get N2O as the gaseous product.

 

[abcde]

Secondly, isn't the Terylene drawn in B8 d (i) of this incorrect? http://www.xtremepapers.me/CIE/Cambridg ... _ms_22.pdf
There should be an oxygen atom to the right of the black box, too as far as I know!

 

[leosco1995]

Yeah, I think it's also wrong..