chem p12...hmm that was a tough one !!!

[histephenson007]

What was the answer for why Aluminium oxide was able to dissolve in NaOH???

 

[intel1993]

question was asking abt being polar of NO not SO2 so NO is non polar..

buddy No is polar.if u search on ineternet ui ll will find it both polar and non polar in places...........
bt as A level student we just have to apply the concepts we learn in alevels.....

As there is an electronegativity diff in both N and O atoms hence polar.......
There is a lone pair on central atom hence polar.............

These were the concepts by the students to find it polar or not.......

 

[intel1993]

the answer of the question about bleach was C as nitrogen was only getting reduced.....but im still confused with the wording of the question

it says nitrogen undergoes a redox reaction which means change in oxidation state only. NOT oxidation + reduction
so the ans was A

hey the term redox refers to the process of the simulataneous oxidation and reduction
hence no chance of only reduction or only oxidation either......................>>>>

 

[alphabravocharlie]

What was the answer for why Aluminium oxide was able to dissolve in NaOH???

Aoa. Well that was simple, as aluminum oxide is amphoteric.

 

[intel1993]

What was the answer for why Aluminium oxide was able to dissolve in NaOH???

due to amphoteric nature of al2o3 it acts as an acid when dissolves in Naoh....................

 

[Sannikutti]

@intel 1993
when i say nacl undergoes redox reaction
means nacl should oxidise and reduced simultaniously
really
like in electrolysis it undergoes reduction and oxidation
or one element goes under reduction and other oxidation
and No was polar so answer was A
and Al2O3 was soluble cuz it can act as an acid
Search in wikipedia or google about redox reaction
and see

 

[Sannikutti]

And Question 40 was A
belive me!

 

[EzioAuditre]

tht bleach question dint hv the equation of NCl3 i guess?? i dunt even remember wht i wrote A or C
wht was the ans to 31 in whch water was added to dilute the acid???

 

[Sannikutti]

@ezio Auditre
B
1 and 2

 

[alphabravocharlie]

I think it was c, i mean the frequency does not decrease, the proportion does and the acid would get weaker so the activation energy required would also change.

 

[Sannikutti]

no man
cuz the activition energy doesnt change
u know why
cuz the activition energy is constant
and frequency does decrease
cuz there will be less acid particle
in particular volume
so less collision
in that
volume

 

[EzioAuditre]

no way 3 was absolutely wrong
whereas i hv a doubt for 2

 

[alphabravocharlie]

Well, i guess the examiners know for sure.

 

[Sannikutti]

guys for question 40
to who ever ever evveeeeeeeeeeeer say it was not first one
i request them to see this website and look at the formula of the compound
http://en.wikipedia.org/wiki/Calcium_acetate
Gone!
now tell me the third choice in that question to finish it off and know the answer

 

[hassam]

it was D for sure .....cos u react butandioic acid with calcium and see...wat happens .,....there are 4 H not 6 @SANNIKUTTI
TRY it out on ur copy now and u ll seE it was D

 

[EzioAuditre]

how cum D butandioic was option 2

 

[hassam]

guyx i dont know y i wrote A for that NCl3 q...is there any chance that it was undergoing redox....cos else they must have written disproportion....and overall reaction in which it participated was redox

 

[hassam]

ya option 2 was butandoic acid...go chek that paper again...nd u tell me y its not d..i cn challenge u now that its D...U JUST PLXX CHECK IT BY DRAWING URSELF

 

[EzioAuditre]

u mean it was ethanoic acid thn?

 

[hassam]

the change in Chiral was +2 and -1.. since the secondary OH will be oxidised to =0 leaving the cholestrol with one less chiral.

DUDE IT WAS +1 AND -1....u said manganate oxidises OH ryt....so y +2 then it must be +1....dont tell me cold doesnt oxidise cos i never saw that thing anywhere