CHEM AND BIO HELP AND TIPS HERE

[Vin]

heyyyyy,does anybody know where i can get CHEM O/N 06 paper without the blank questions? X(

I dunno wat blank ques r u talking abt

[Baladya]

heyyyyy,does anybody know where i can get CHEM O/N 06 paper without the blank questions? X(

lol wtf is that xD 

[Ghost Of Highbury]

ok u have to go with colorless, because Chlorine is not acidic or basic. the only option with colorless...

[Vin]

Thanks, what about Q13??

Ok remember when concentrated NaCl is electrolyzed:
First the solution contains Na⁺ Cl^- and H⁺ and OH^- (from water). The positive inos go to the cathode, and negative ions to the anode.

At the CATHODE
the H+ ions accept electrons, since it is less reactive than Na (always elements which is more reactive 'likes' to stay in the ionic form)
2H⁺  +  2e-  ---> H2

At the ANODE
the Cl- ions give up the electrons more readily than the OH- ions do.
2Cl^-  -->  Cl₂  +  2e-

what left in the solution is Na+ and OH- which combine to form NaOH

in your ques ..is 'D' .. the indicator solution turns blue at -ve as NaOH is produced .. Chlorine doesnt  show any change in presence of an indicator solution

jus understand the concept ..



see in this question u hav to act smart .. look at the options .. u now kno tht NaOH is produced so the indicator turns blue ..there are two options with 'bule/purple' A and B .. now see A .. at -ve 'red' is given which is not possible because no acid it produced during the reaction so u r left with D ..

[The Golden Girl =D]

Ok remember when concentrated NaCl is electrolyzed:
First the solution contains Na⁺ Cl^- and H⁺ and OH^- (from water). The positive inos go to the cathode, and negative ions to the anode.

At the CATHODE
the H+ ions accept electrons, since it is less reactive than Na (always elements which is more reactive 'likes' to stay in the ionic form)
2H⁺  +  2e-  ---> H2

At the ANODE
the Cl- ions give up the electrons more readily than the OH- ions do.
2Cl^-  -->  Cl₂  +  2e-

what left in the solution is Na+ and OH- which combine to form NaOH

in your ques ..is 'D' .. the indicator solution turns blue at -ve as NaOH is produced .. Chlorine doesnt  show any change in presence of an indicator solution

jus understand the concept ..



see in this question u hav to act smart .. look at the options .. u now kno tht NaOH is produced so the indicator turns blue ..there are two options with 'bule/purple' A and B .. now see A .. at -ve 'red' is given which is not possible because no acid it produced during the reaction so u r left with D ..

 u said H2 goes to cathode , then y u said sodium hydroxide changes indicator to blue when it is at the bottom not even close to the +ve electrode

[the_grim_reaper]

for anions:
someone -sulphate
only-hydroxide(gives oxygen on oxidation)
nice-nitrate
cleans-chloride
broken -bromide
items-iodide

Are you sure??? I've always come across series that put nitrate above hydroxide.

Plus one final thing people, in June 2000, shouldn't question 30 be C??? (Paper 1 Chemistry)

[jellybeans]

I dunno wat blank ques r u talking abt

... there .. blank questions

[Vin]

 u said H2 goes to cathode , then y u said sodium hydroxide changes indicator to blue when it is at the bottom not even close to the +ve electrode

see in this question u hav to act smart .. look at the options .. u now kno tht NaOH is produced so the indicator turns blue ..there are two options with 'bule/purple' A and B .. now see A .. at -ve 'red' is given which is not possible because no acid it produced during the reaction so u r left with D ..

[Baladya]

So what do u want us to do? Make a new question paper xD

[The Golden Girl =D]

see in this question u hav to act smart .. look at the options .. u now kno tht NaOH is produced so the indicator turns blue ..there are two options with 'bule/purple' A and B .. now see A .. at -ve 'red' is given which is not possible because no acid it produced during the reaction so u r left with D ..

wait isn't hydrgoen an acidic gas 

[Ghost Of Highbury]

Are you sure??? I've always come across series that put nitrate above hydroxide.

Plus one final thing people, in June 2000, shouldn't question 30 be C??? (Paper 1 Chemistry)

OOPS! THANKS, ITS ABOVE HYDROXIDE

[Baladya]

wait isn't hydrgoen an acidic gas 

http://wiki.answers.com/Q/What_is_an_acidic_hydrogen_atom

Read this...

[The Golden Girl =D]

http://wiki.answers.com/Q/What_is_an_acidic_hydrogen_atom

Read this...

tayeeb ma it turns to be an ion hence is ACIDIC!!

[Vin]

wait isn't hydrgoen an acidic gas 

yes but it has to dissociate with water to give H⁺ to show its acidity ..

[Baladya]

tayeeb ma it turns to be an ion hence is ACIDIC!!

I dont know ur question but ur right and VIN is right in ur last posts