Since it was under reflux, I wrote ethanoic acid and the test was adding acid and seeing if limewater turns cloudy due to the presence of CO2 (I think).

What did you write for the thiosulphate oxidation numbers? I messed that one up cuz I kept getting 2.5 for sulfur. Also, what organic solvent did you write for Iodine?

Reply 9

Marzi20000

4

Original post by Erica.kh

Since it was under reflux, I wrote ethanoic acid and the test was adding acid and seeing if limewater turns cloudy due to the presence of CO2 (I think).

What did you write for the thiosulphate oxidation numbers? I messed that one up cuz I kept getting 2.5 for sulfur. Also, what organic solvent did you write for Iodine?

Welp. I wrote ethanal since it was being distilled, was cotemplating whether I should write Ethanoic acid or Ethanal. For the oxidation number, Iodine got reduced from 0 to -1 while Sulfur got oxidised from +4 to +10 I think.

Reply 10

Erica.kh

OP

11

Original post by Marzi20000

Welp. I wrote ethanal since it was being distilled, was cotemplating whether I should write Ethanoic acid or Ethanal. For the oxidation number, Iodine got reduced from 0 to -1 while Sulfur got oxidised from +4 to +10 I think.

Dang, totally messed up the disproportionation question 😧. And I might have completely miss read the ethanol Q and maybe it is ethanal. Fingers crossed :s-smilie:

Reply 11

somia007

9

i got 0.022525 ,something along these lines for the last question.

Reply 12

somia007

9

there was this question about iodine and like using an orgnic layer...
what did you guys write for the organic solvent and colour change?

Reply 13

Marzi20000

4

Original post by somia007

there was this question about iodine and like using an orgnic layer...
what did you guys write for the organic solvent and colour change?

I wrote Hexane since iodine is not fully soluble in it and that the colour change will be from reddish brown to red-pink.

Reply 14

Foxtrot2233

5

Original post by Erica.kh

Since it was under reflux, I wrote ethanoic acid and the test was adding acid and seeing if limewater turns cloudy due to the presence of CO2 (I think).

What did you write for the thiosulphate oxidation numbers? I messed that one up cuz I kept getting 2.5 for sulfur. Also, what organic solvent did you write for Iodine?

I got 2.5 for sulphur as well. Didn't get +4 to +10. not sure which one is correct.

Reply 15

Erica.kh

OP

11

Yah I wrote Hexane too, but I said the colour change was to purple cuz it's a hydrocarbon. And idk, half oxidisation numbers don't look right so :s-smilie:

Reply 16

IGCSEsurvivor

12

how was unit 3?