Chemistry MCQ thread...

[Zishi]

EQUILIBRIUM ONE IS RYT BUT PARAVASTATIN one is D

Right. I got these answers. Potassium manganate(when heated under reflux) is so strong oxidising agent that it tends to break the chains.

which chains are most probably to be broken ?

Chains with hydroxyl groups.

 

[RafaySid]

Can anyone tell me from where does '1.1' come into the partial pressure calculations as the answer is D??? :evil:

 

[Mobeen]

Can anyone tell me from where does '1.1' come into the partial pressure calculations??? :evil:

is the answer C?

 

[hassam]

 

[hassam]

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

 

[RafaySid]

Can anyone tell me from where does '1.1' come into the partial pressure calculations??? :evil:

is the answer C?

No, it's D.

 

[Mobeen]

then how can it be 1.1 :S :S

 

[RafaySid]

then how can it be 1.1 :S :S

That's what I'm confused about. :%)

 

[aleem420]

25 High-energy irradiation in the stratosphere produces radicals from chlorofluoroalkanes, commonly
known as CFCs.
Which radical could result from this irradiation of CHFClCF2Cl?
A CHFClCFCl
B CHClCF2Cl
C CHFCF2Cl
D CFClCF2Cl

Plz helpppppppp.....................

 

[Aloo007]

@ rafaysid 0.8x + 0.2x + o.2x/2 = 1atm by the equation x=1/1.1 so......

 

[Mobeen]

25 High-energy irradiation in the stratosphere produces radicals from chlorofluoroalkanes, commonly
known as CFCs.
Which radical could result from this irradiation of CHFClCF2Cl?
A CHFClCFCl
B CHClCF2Cl
C CHFCF2Cl
D CFClCF2Cl

Plz helpppppppp.....................

this question has dots over the radical carbons without which u cant solve it .. its better if u paste a screenshot !

 

[Aloo007]

@aleem ur ans is C because uv light breaks c-cl bond as it is the weakest

 

[histephenson007]

25 High-energy irradiation in the stratosphere produces radicals from chlorofluoroalkanes, commonly
known as CFCs.
Which radical could result from this irradiation of CHFClCF2Cl?
A CHFClCFCl
B CHClCF2Cl
C CHFCF2Cl
D CFClCF2Cl

Plz helpppppppp.....................

one thing u need to know about this is that at stratosphere, the energy given by the UV rays isn't enough to break the 'C-F' bond...
u can continue with the question urself

 

[xHazeMx]

25 High-energy irradiation in the stratosphere produces radicals from chlorofluoroalkanes, commonly
known as CFCs.
Which radical could result from this irradiation of CHFClCF2Cl?
A CHFClCFCl
B CHClCF2Cl
C CHFCF2Cl
D CFClCF2Cl

Plz helpppppppp.....................

this question has dots over the radical carbons without which u cant solve it .. its better if u paste a screenshot !

it's C, the C-F bond is stronger than the C-Cl bond. so the radical which would be resulted must be CL*

 

[RafaySid]

@ rafaysid 0.8x + 0.2x + o.2x/2 = 1atm by the equation x=1/1.1 so......

Thanks Aleena, and you have yourself your first Thank! :Yahoo!:

 

[abdullah181994]

please explian it to me

 

[Aloo007]

@ rafaysid hahaha it says aloo as in a patato not aleena

 

[abdullah181994]

plz explain

 

[abdullah181994]

no one is answering my questions today

 

[hassam]

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