Biology; Chemistry; Physics: Post your doubts here!

[MustafaMotani]

your wrong..

xD he is damn right... Coz when u heat a meatl rod from one end electrons there diffuse to the colder parts it is called free electron diffusion

 

[MustafaMotani]

Another confusion everyone *heads up*

When we label the axes on a graph, if one of the axes is supposed to be 'nuber of sth.' lets say "number of bounces" and is represented as "N" . how do we write it?? i mean we can't write the unit for it but we are supposed to label the graph like "l/cm" ryt?? shud we leave it at that or what??

just ryt number of bounces ... it really depends on d situation

 

[MustafaMotani]

Ok just someone tell if catalysts affects equilibrium in reversible reactions.... I know that it reduces activation energy but it doesnt increase the amount of actual product at the end ... Help will be appreciated.. >

 

[Dukeofwin]

How to find the focal length?
Below is my guess, correct me if i'm wrong!
.
Keep objects at varying lengths from the lens, wherever the the image formed is of the same size as the object that distance should be marked.
That distance should be 2F! Halving it would give the focal length!

 

[Dukeofwin]

Ok just someone tell if catalysts affects equilibrium in reversible reactions.... I know that it reduces activation energy but it doesnt increase the amount of actual product at the end ... Help will be appreciated.. >

No it never increases the product!

 

[A star]

why? could you explain it a bit, like why does it happen? i have never understood that concept myself.

you see just remember silver as a metal that is unreactive to such an extent that it will decompose redily to form metal. just like in chloride. as soon as recieves soler energy it decomposes.

 

[MustafaMotani]

No it never increases the product!

my ques was does it effects equilibrium ?? forward backward or nothing.. ??

 

[ashiqbal]

its A

ok thats confusing!

 

[A star]

No it never increases the product!

more elaboration: if catalyst added increase in rate of forward reaction=increase in rate of backward hence yield is constant

 

[A star]

my ques was does it effects equilibrium ?? forward backward or nothing.. ??

see my post and my question 1 last part http://www.xtremepapers.com/papers/...onal O Level/Physics (5054)/5054_s03_qp_4.pdf

 

[daredevil]

look...
in conduction, the molecules of the solid vibrate vigourously (for obv reasons) and they pass their kinetic energy but hitting the other molecules and thus heat travels..
let me ask you a question , how would the electrons carry heat?? they move on a orbit ..:|
plus the convection is movement of molecules so that can never happen in a solid (for obv reasons)

XCUSE ME!! he electrons of metals are NOT in the orbits. they are delocalised!! that's the whole point of the metals being good conductors because they have a SEA OF ELECtRONS that helps to carry the heat/electricity!

 

[MustafaMotani]

How to find the focal length?
Below is my guess, correct me if i'm wrong!
.
Keep objects at varying lengths from the lens, wherever the the image formed is of the same size as the object that distance should be marked.
That distance should be 2F! Halving it would give the focal length!

I would say vary the distance of lens from a whit screen with light source near optical axis (horizon) ...when u get SHARPEST image measure perpendicular distance btween screen and lens

 

[A star]

see my post and my question 1 last part http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_s03_qp_4.pdf

anyone please respond

 

[MustafaMotani]

more elaboration: if catalyst added increase in rate of forward reaction=increase in rate of backward hence yield is constant

Thats what i was asking thank you its quite sensible...

 

[Dukeofwin]

B

I would say vary the distance of lens from a whit screen with light source near optical axis (horizon) ...when u get SHARPEST image measure perpendicular distance btween screen and lens

But would my method be correct?

 

[MustafaMotani]

anyone please respond

u see xy gievs a constant i.e. 5400 which shows that y is directly proportional to 1/x

 

[ashiqbal]

please explain this question if anyone can:

From which ammonium salt can the greatest mass of ammonia b obtained?
A) 0.5 mole (NH3)2PO4
B) 0.5 mole (NH4)2SO4
C) 1 mole NH4Cl
D) 1 mole NH4NO3

 

[MustafaMotani]

B
But would my method be correct?

I dont know.. I think it should be but your method seems complicated

 

[ashiqbal]

B
But would my method be correct?

i would go with mustafamotani

 

[A star]

u see xy gievs a constant i.e. 5400 which shows that y is directly proportional to 1/x

my xy values are varying only two are coming 5400 one is comming 3000 and other 9900

 

[Dukeofwin]

anyone please respond

Thus you can add a constant and make a more mark encouraging equation of XY=k and Y=k/x

 

[MustafaMotani]

please explain this question if anyone can:

From which ammonium salt can the greatest mass of ammonia b obtained?
A) 0.5 mole (NH3)2PO4
B) 0.5 mole (NH4)2SO4
C) 1 mole NH4Cl
D) 1 mole NH4NO3

frst mcq should have NH4 instead of NH3