Chemistry doubt

[red_911]

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 ..

lol...Thanks alot ... but y does the indicator solution turns blue only at -ve electrodde and not the whole solution ?

[Vin]

lol...Thanks alot ... but y does the indicator solution turns blue only at -ve electrodde and not the whole solution ?

good ques .. see in this question u hav to act smart .. i think i forgot to mention .. 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 ..

[nerdvictim]

hey, between which elements can you find carbon in the reactivity series ?! 

[Vin]

hey, between which elements can you find carbon in the reactivity series ?! 

LEARN it !

[nerdvictim]

LEARN it !

i sure will! thank you 

[Vin]

i sure will! thank you 

sure .. your welcome

[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 ..

 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

[Ghost Of Highbury]

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 ..

it isnt concentrated, its aqueous .!!!

[Vin]

it isnt concentrated, its aqueous .!!!

AADI U GAVE ME AN ATTACK !! ITS CONCENTRATED AQ. NaCl

[8T]

hi By the way below copper theres mercury Hg
i have a question mj 04 p1 q 30
why is the answer C?
can sum1 explain plz

[Ghost Of Highbury]

hi By the way below copper theres mercury Hg
i have a question mj 04 p1 q 30
why is the answer C?
can sum1 explain plz

the original is dilute NaOH because it has water in it...so say its pH is 10 (>7, because its alkali)

the distillate is water so pH = 7

the NaOH in the flask doesnt have any water left, so its concentrates that means its pH >10 (dilute NaOH)

thus , C

[rhea]

hey can you tell me what colour chnages occur when universal indicator comes in contact with
hydrogen
oxygen
ammonia

and i thought acid /salt added to UI would not change the colour of UI.
right?

[8T]

UI in neutral solutions is green
in alkali blue if weak, violet if strong
in acid red & u do not test for gases with UI
Thanks A@di

[Vin]

hey can you tell me what colour chnages occur when universal indicator comes in contact with
hydrogen
oxygen
ammonia

and i thought acid /salt added to UI would not change the colour of UI.
right?

hydrogen - no change
oxygen - no change
ammonia - blue/purple

yes it does .. right click and click view image

[rhea]

hydrogen - no change
oxygen - no change
ammonia - blue/purple

yes it does .. right click and click view image

umm this means phenolphthalein is not an UI?