Physics, Chemistry and Biology: Post your doubts here!

[sma786]

i think u tagged the paper wrong!!

uff ..m sorry
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s09_qp_3.pdf
Question 2, variant 1 .. the electrolysis table .. how do we know all thiss ??

 

[EpicLol]

uff ..m sorry
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s09_qp_3.pdf
Question 2, variant 1 .. the electrolysis table .. how do we know all thiss ??

There are a few things u need to know about electrolysis first....whenever its molten then the metal forms at the cathode and the other at the anode
But when there is aqueous solution, then there are H+ and OH- ions to consider as well....and there are like 2 exceptions u need to remember...
Whenever there is a chloride solution, then if its dilute then OH- goes out instead of Cl- and at cathode H+ ions go out so after a while the solution will become more concentrated as H+ and OH- are leaving....therefore when its concentrated, Cl- goes out and H+ goes out this leaves us with Metal hydroxide.....

Hope this helps

 

[purplerox]

can some1 tell me wat exactly PARALLAX error is..coz it alwayz cums in d physics ppr...i noe its a dum qs but plzzz..!!

 

[sma786]

There are a few things u need to know about electrolysis first....whenever its molten then the metal forms at the cathode and the other at the anode
But when there is aqueous solution, then there are H+ and OH- ions to consider as well....and there are like 2 exceptions u need to remember...
Whenever there is a chloride solution, then if its dilute then OH- goes out instead of Cl- and at cathode H+ ions go out so after a while the solution will become more concentrated as H+ and OH- are leaving....therefore when its concentrated, Cl- goes out and H+ goes out this leaves us with Metal hydroxide.....

Hope this helps

so when molten, metal metal
when concen. metal hydroxide
when aqu, oxygen n hydrogen, ryt??

 

[Dashexdan]

so when molten, metal metal
when concen. metal hydroxide
when aqu, oxygen n hydrogen, ryt??

when molten+metal non metal
whn conc. = metal and non-metal
whn dilute=metal and hydroxide
and in aqu state the metal at cathode cud be either hydrogen or the other metal in the reaction depending on the reactivity series and the one below in the reactivity series always goes to cathode!!
hope u understood it

 

[thats_me]

when molten+metal non metal
whn conc. = metal and non-metal
whn dilute=metal and hydroxide
and in aqu state the metal at cathode cud be either hydrogen or the other metal in the reaction depending on the reactivity series and the one below in the reactivity series always goes to cathode!!
hope u understood it

arent aqueous n dilute the same?

 

[Dashexdan]

can some1 tell me wat exactly PARALLAX error is..coz it alwayz cums in d physics ppr...i noe its a dum qs but plzzz..!!

it is when ur line of sight is not perpendicular the measurement on the object u r reading from!! eg ruler
http://aphysicsteacher.blogspot.com/2009/12/what-is-parallax-error.html

 

[Dashexdan]

arent aqueous n dilute the same?

yes they r the same

 

[Maz]

yes they r the same

Are you sure? An aqueous solution can also be a concentrated solution.(I think so)

 

[Dashexdan]

Are you sure? An aqueous solution can also be a concentrated solution.(I think so)

yeah ....bt if its only aqueous written there so we take the solution as dilute!!​

 

[thats_me]

Are you sure? An aqueous solution can also be a concentrated solution.(I think so)

no for that its "concentrated aqueous"

 

[thats_me]

I see. So, if concentrated is not mentioned along with aqueous then we take it to be dilute?

Yep!

 

[sma786]

Can i get a good definition of equilibrium ?

 

[MoAwwami]

arent u done with physics paper1?!?

Im in 9th grade, i dont my IG's till next year, but our school exams are from IG past paper (for preparation).

 

[thats_me]

Can i get a good definition of equilibrium ?

When the rate of forward reaction is equal to the rate of backward reaction, the reaction is said to be at equilibrium

 

[sma786]

Im in 9th grade, i dont my IG's till next year, but our school exams are from IG past paper (for preparation).

ur so lucky u have 1 more year

 

[sma786]

When the rate of forward reaction is equal to the rate of backward reaction the reaction is said to be at equilibrium

thnku

 

[thats_me]

thnku

anytime!

 

[MoAwwami]

Can i get a good definition of equilibrium ?

Physics : an object is in equilibrium when 1. Total forces in one direction = total forces on the opposite direction
or 2. Total Clock Wise moment = Total Anti Clock Wise moment

chemistry : (Reversible reactions in equilibrium) Rate of Forward reaction = Rate of backward reaction

hope this helps

 

[sma786]

Physics : an object is in equilibrium when 1. Total forces in one direction = total forces on the opposite direction
or 2. Total Clock Wise moment = Total Anti Clock Wise moment

chemistry : (Reversible reactions in equilibrium) Rate of Forward reaction = Rate of backward reaction

hope this helps

thnku , it did