CSSA chemistry (5 Viewers)

[jamesfirst]

My teacher just told me I had a bad attitude and that he didn't like me. :/

lol owned.

 

[jamesfirst]

We had a question on dry cell/lead acid cell vs another cell in terms of chemistry and impact on society.

man I nearly got owned in that q.


I didnt study button cell, but I guessed the chemistry part for it. Just did redox of silver and zinc.

 

[Joy_2575]

Hi Guys,

I've started my Chemistry blog..

Comments are welcome!

http://acehsc.wordpress.com/

Looks good!

 

[muzeikchun852]

man I nearly got owned in that q.


I didnt study button cell, but I guessed the chemistry part for it. Just did redox of silver and zinc.

button cell is zinc and silver oxide.

 

[pinkcupcakes]

button cell is zinc and silver oxide.

i had a blank and forgot my equations for the button cell in the exam.. fml

 

[muzeikchun852]

i had a blank and forgot my equations for the button cell in the exam.. fml

if i remember it correctly:
Zn -> Zn2+ + 2e-
Ag2O + H2O + 2e- -> 2Ag + 2OH-

 

[UnrealAnchovies]

if i remember it correctly:
Zn -> Zn2+ + 2e-
Ag2O + H2O + 2e- -> 2Ag + 2OH-

different to the one i use (button cell also).. my anode is something like: Zn + 2OH- ---> Zn(OH)2 + 2e-

 

[MagnificentOne]

if i remember it correctly:
Zn -> Zn2+ + 2e-
Ag2O + H2O + 2e- -> 2Ag + 2OH-

i think your reduction equation is wrong?

 

[Chambalam]

different to the one i use (button cell also).. my anode is something like: Zn + 2OH- ---> Zn(OH)2 + 2e-

Its the same thing. Muzeik's is just an oxidation half-equation from the table, yours just has spectator ions on either side

 

[imZerroo]

My teacher just told me I had a bad attitude and that he didn't like me. :/

my teacher almost said the same thing, when i wanted her to sign my dropping sheet.
BUT
then she said she think im really smart but i dont work hard enough and i have a bad attitude towards chem
i took that as a compliment and didn't drop. wanna kill that s.o.b now. im not smart enough to do chem, i worked hard at it. :/

 

[Dylanamali]

Does anyone remember the MC question where it was like zinc is added to hydrogen. And it said which is the stronger reductant/which is the stronger oxidant.. What did people put?

 

[imZerroo]

I put Zn is stronger reductant.
its either that or H+ are stronger oxidant.
So I guessed the Zn.
Took me 5 minutes to know wtf the q. was asking me TBH.

 

[Dylanamali]

I put Zn is stronger reductant.
its either that or H+ are stronger oxidant.
So I guessed the Zn.
Took me 5 minutes to know wtf the q. was asking me TBH.

Yeah I was a bit confused.. because both are correct aren't they.. In the end I was just like wtf. and ended up putting B - which is zinc is the stronger reductant, aswell.

 

[Riproot]

Yeah I was a bit confused.. because both are correct aren't they.. In the end I was just like wtf. and ended up putting B - which is zinc is the stronger reductant, aswell.

I think I put this because the oxidiser doesn't start the reaction the reductor does. Kinda. I don't even...

 

[umz93]

Crap another question i got wrong :/

 

[imZerroo]

It was soo hard, after my first go at MC, I ticked atleast 12 questions that I made sure I look back on. Spent so much time on MC.

 

[Dylanamali]

It was soo hard, after my first go at MC, I ticked atleast 12 questions that I made sure I look back on. Spent so much time on MC.

I RECKON! usually I go through MC in like 15 mins - this one took me 30 mins .. =/
and after discussing things today with ppl I found out I got another few wrong.. so looks like I MIGHT just scrap in the 80's .. --

 

[Riproot]

i reckon! Usually i go through mc in like 15 mins - this one took me 30 mins .. =/

fucking exactly the same!!!

 

[muzeikchun852]

i think your reduction equation is wrong?

i think it's right. it doesnt have to be neutral.

I put Zn is stronger reductant.
its either that or H+ are stronger oxidant.
So I guessed the Zn.
Took me 5 minutes to know wtf the q. was asking me TBH.

i putted H+ are stronger oxidant.

if i remember it right, the cathode produces the hydrogen gas. so the hydrogen has must be a stronger oxidant than the solution's ion (i forgot what is it).

 

[_deloso]

Yeah I was a bit confused.. because both are correct aren't they.. In the end I was just like wtf. and ended up putting B - which is zinc is the stronger reductant, aswell.

that's correct cos Zinc is oxidising thus it is a reductant as it reduces hydrogen. But you can also argue that Hydrogen is a stronger oxidant (which was the other answer) as hydrogen causes zinc to oxidise. But I think Zinc starts the redox reaction so yeah I answered Zinc is the stronger reductant. hopefully it's right