A2 OCR Chemistry B F334 - June 2015

which observation do you mean?

what did everyone put for the infrared spec?

I think he means the iron hydroxide one!

I put the 2 one because there was an OH peak, again no idea if that right!

What about the positive tests for the aromatic compounds?

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Reply 401

GrahamRianna

That was so hard compared to past papers, didn't have time to check my answers either :frown:

how did others find it?
There's my uni place gone

For the DNA 5 marker is it A-T 2 H bonds and C-G 3?

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Reply 402

Charletitia

3

What was the choking vapour? All that I could figure was that ethanoic acid had been made!

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Reply 403

GrahamRianna

Original post by Fred Cantoni

I think he means the iron hydroxide one!

I put the 2 one because there was an OH peak, again no idea if that right!

What about the positive tests for the aromatic compounds?

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I put the one with 2 too.
Test for phenol with Iron (III) chloride for one and then test for carboxylic acids with carbonates and CO2 should be released

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Reply 404

MMB07

1

For the question comparing IMB in cellulose and polyester is it just me or did they have the exact same bonds? PD-PD and ID-ID?

Reply 405

BrokenS0ulz

3

Was the ion VOsubscript2+.

Reply 406

Fred Cantoni

2

Original post by GrahamRianna

I put the one with 2 too.
Test for phenol with Iron (III) chloride for one and then test for carboxylic acids with carbonates and CO2 should be released

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Yeah I got both of those tests! Oh might not of gone as bad as I thought :smile:

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Reply 407

Fred Cantoni

2

Original post by MMB07

For the question comparing IMB in cellulose and polyester is it just me or did they have the exact same bonds? PD-PD and ID-ID?

Yeah I got the same, no idea if it's right!

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Reply 408

lifeistoff

12

Disappointed at the lack of chirality in that paper

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Reply 409

Charletitia

3

Original post by MMB07

For the question comparing IMB in cellulose and polyester is it just me or did they have the exact same bonds? PD-PD and ID-ID?

I put PD PD for polyester and ID ID for cellulose because I thought it would be too big a molecule??? Was a total guess!

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Reply 410

username1082804

3

Not sure if it's right but my answers were:
-ammonia
-97% for the % by mass
-for IR spectrum, I put the tri- one
-For the one reaction with NaI, I put VO2^+
-chlorine gas (for the toxic gas)
-For the reaction of Fe2+ with NaOH:
observation before: colourless solution
observation after: a precipitate formed
Fe2+ (aq) + 2OH- (aq) >> Fe(OH)2 (s)
-positive test:
for C, I put neutral iron (III) chloride due to phenol group so purple solution
for D, I put reacting with sodium carbonate, as carboxylic acid reacts with NaCO3 so fizzes
-And Pd-Pd and ID-ID for both compounds

(edited 8 years ago)

Reply 411

username911777

15

**** that paper was hard

Reply 412

Beasttty

6

Original post by chococup123

Not sure if it's right but my answers were:
-ammonia
-97% for the % by mass
-for IR spectrum, I put the tri- one
-For the one reaction with NaI, I put VO2^+
-chlorine gas (for the toxic gas)
-For the reaction of Fe2+ with NaOH:
observation before: colourless solution
observation after: a precipitate formed
Fe2+ (aq) + 2OH- (aq) >> Fe(OH)2 (s)
-positive test:
for C, I put neutral iron (III) chloride due to phenol group so purple solution
for D, I put reacting with sodium carbonate, as carboxylic acid reacts with NaCO3 so fizzes

I agree with everything except for the observation. I put fe2+ is yellow in solution, precipitate formed would be yellow precipitate
I'm wrong though. Fe2+ is green in solution

Reply 413

MMB07

1

Original post by chococup123

Not sure if it's right but my answers were:
-ammonia
-97% for the % by mass
-for IR spectrum, I put the tri- one
-For the one reaction with NaI, I put VO2^+
-chlorine gas (for the toxic gas)
-For the reaction of Fe2+ with NaOH:
observation before: colourless solution
observation after: a precipitate formed
Fe2+ (aq) + 2OH- (aq) >> Fe(OH)2 (s)
-positive test:
for C, I put neutral iron (III) chloride due to phenol group so purple solution
for D, I put reacting with sodium carbonate, as carboxylic acid reacts with NaCO3 so fizzes
-And Pd-Pd and ID-ID for both compounds

Was the solution in the precipitate question colourless before? I thought it was green because of fe2+ ions in solution

Reply 414

Beasttty

6

Anyone put IDID for the first then PD-PD and ID ID for the second?

Reply 415

username1082804

3

Original post by Beasttty

I agree with everything except for the observation. I put fe2+ is yellow in solution, precipitate formed would be yellow precipitate
I'm wrong though. Fe2+ is green in solution