Chemistery P22 (As Strustured questions)

[JK_1995_15]

overall the test was easy but it had its difficulties ....Please ive corrected the test if someone waants explanations do ask

 

[sakura9542]

i did a different variant but i wanna ask sumting... the question asked for the definition of a free radical.. i wrote it must have a lone pair.. is it still acceptable coz i didn't write da term "unpair electron"?? pls reply anyone..

 

[loly23]

@san
it's a SHE!!!and yeah she's a great teacher!!
we gonna share our results later then..

 

[eva 21]

oh yeah... forgot abt that...
what did u guys write for the definition of free radicals?
and for homolytic fission?
i'm a bit worried abt the definitions... :?

what properties did u give for the CFCs? for being used as an aerosol repellent?

and what was the reason that u guys wrote? for problems using alkanes instead of CFCs?

what was your answer for the heat evolved in the enthalpy change question???
:? :? :?

 

[JK_1995_15]

homolytic fission is the process by which a covalent bond is broken between two atom, where each atom gets one of the bonding pair electrons forming two free radicals that what i put

Properties were: Non-flamma le and non toxic

 

[soumayya]

ques 5 was a bit too short..only 3 marks..
i got NaX as NaBr...i fink for the second i put Br2 or SO2...

 

[JK_1995_15]

tell me about the test in general i can help a

 

[jerry]

u guys i completely forgot what the last question was about!
can u plz tel wat the question was about and where did u get NaBr abd Nax?
someone?

 

[JK_1995_15]

Sure jerry.. Now listen... u had phosphoric acid + a metal halide -----> it said on the question that a red orange gas was evolved indicating the presence of Bromine... Soo the sodium halide could only be nabr

The other gas that was evolved if H2SO4 was used would be SO2 because if you look to the equatiom : H2SO4 + HBr -------> SO2 + BR2 + H2O



tHE LAST question why couldn t h2so4 be used to obtain HX is because H2SO4 would oxidise HX further to its elemental state forming X2

 

[skyfox]

homolytic fission is the process by which a covalent bond is broken between two atom, where each atom gets one of the bonding pair electrons forming two free radicals that what i put

Properties were: Non-flamma le and non toxic

the properties can be "inert" also..

 

[eva 21]

Sure jerry.. Now listen... u had phosphoric acid + a metal halide -----> it said on the question that a red orange gas was evolved indicating the presence of Bromine... Soo the sodium halide could only be nabr

The other gas that was evolved if H2SO4 was used would be SO2 because if you look to the equatiom : H2SO4 + HBr -------> SO2 + BR2 + H2O



tHE LAST question why couldn t h2so4 be used to obtain HX is because H2SO4 would oxidise HX further to its elemental state forming X2

yaaaaaaaaaaaay! i got that right!!!!
(clapping my hands in joy!)

 

[eva 21]

homolytic fission is the process by which a covalent bond is broken between two atom, where each atom gets one of the bonding pair electrons forming two free radicals that what i put

Properties were: Non-flamma le and non toxic

the properties can be "inert" also..

thank goodness...
i thot i was done for...
cuz i also wrote inert and non toxic...
(yay! its ryt!)
:mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen:
(Aalhamdurillaah...)

 

[JK_1995_15]

Applications exploit the low toxicity, low reactivity, and low flammability of the CFCs and HCFCs. - quote from wikipedia..... so either non-flmmavle inert and non toxic were good

 

[eva 21]

Applications exploit the low toxicity, low reactivity, and low flammability of the CFCs and HCFCs. - quote from wikipedia..... so either non-flmmavle inert and non toxic were good

yaaaaaaaaaaaaaaaaay !

 

[JK_1995_15]

Im just here to help !!!!!!!!!!! any help needed please do ask!!!!!!!

 

[P3Rf3cTStRaNG3R]

CxHy + (x+y/4)O2 ---> xCO2 + (y/2) H2O
i had it in my copybook so im sure it is the answer

 

[JK_1995_15]

yes it is ! i put down the same equation

 

[JK_1995_15]

let me know for further doubts

 

[xxo]

Could the property for CFC be volitile? And could the ansswer for the last part be that SO@ is released which is an atmospheric pollutant? And what do you think would be the g.t. for this paper?

 

[eva 21]

i gess i'v been infected with late exam amnesia...
(i cant remember a THING anymore!) :geek: :?: :!:

anyone remember what qestion number 3 was? :shock: