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Chemistry MCQ thread...

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dude i was tryin to figure out Q5 dont get it wats the ans? but the other Question is D as N goes from -3 to +1 and +5 to +1 changes are +4 and -4
 
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answer is 3 i dont know how to explain it but from left to right one is fromed from CH3 the other from CH2 then the third from any of the CH3 as they all are the same
 
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hassam said:
1.2 g of an oxide MO of a metal M was dissolved in an excess sulfuric acid. 25.0 cm3 of
0.10 mol dm−3 potassium dichromate(VI) solution was required to oxidise M2+ to M3+.
What is the relative atomic mass of M?
A 52
B 56
C 64
D 80

ans : C ? yes?
 
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Hahah! I was stuck on this one for a min 15 mins today. Can anyone explain the balancing of this disproportionation reaction by oxidation numbers. I know the answer is B but plz c'mon somebody..
 
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ans B
I2 is is formed after gain of electron (in HIO, oxidation state of I is +1, so gain 2 electrons to form I2)
in HIO3, I is oxidise by loosing 4 electron.
to keep loss ang gain of electron same, there must be 2 mole of I2.
Best wishes for tomorrow :)
 
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intel1993 said:
hey why cant A be the answer???
Ans is D
already it contain 8 chiral carbon, and 4 ll more.
2ndly
A is wrong because 4 mole required,not 3( 3 for alcohol and one for acid)
B is wrong because 4(may 5) mole of H2 required, 2 for alkene, one for ketone and one(may be 2) for acid.
C is wrong, because in acidic medium, hydrolysis ll occurred
 
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