OCR AS Salters Chemistry F332 - Wednesday 23rd May 2012 1:30pm

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For the question why can it not be used as cleaning solvents... do you reckon for just saying it doesn't contain chlorine and it's a CFC will be okay?

it doesn't contain chlorine should be correct as chlorine is a disinfectant, i wrote it is flammable so i'm hoping that's right too :frown:

Reply 781

Beffnaay

It's the steam one! It was soooo cheeky for putting water instead of steam, was looking at it for ages and then realised! Phosphoric acid catalyst, 300 degrees C and 60 ATM

Reply 782

Dixie

for the why can it not be used as a solvent i was gonna say flammable but then i put coz it will be gas at room temp and i swear the same question came up in maybe a legacy paper that i did? i think flammable is the right answer now though :/ lol fml.

Reply 783

vishalb

Original post by Beffnaay

It's the steam one! It was soooo cheeky for putting water instead of steam, was looking at it for ages and then realised! Phosphoric acid catalyst, 300 degrees C and 60 ATM

in markschemes they do usually allow the use of both sulphuric acid and phosphoric acid so they should allow both? :frown:

and i just put high temp/high pressure cos i wasn't sure exactly hope i'll get the mark for it? :/

Reply 784

Zhy

Did anyone else have to get extra paper? The space at the back wasn't enough! :frown:

Reply 785

Rhiiannaa

What did people get for the titration questions?

Reply 786

AGrumpyMole

Original post by Rhiiannaa

What did people get for the titration questions?

the 3 sig fig one was 0.0261

Reply 787

*mike

Original post by mortaz786

c15 h22 0

reacting with bromine

c15 h22 0 +br2 -----> c15h220br2

electrophilic addition reaction

Surely it would be

c15 h22 0 +2br2 -----> c15h220br4

Because it had two double bonds that could open up...

Reply 788

Pucilowski

Original post by *mike

Surely it would be

c15 h22 0 +2br2 -----> c15h220br4

Because it had two double bonds that could open up...

Yeah, you're right.

Does no one remember what the molecule was called though? I counted 21 hydrogens and it's killing me.

(edited 11 years ago)

Reply 789

Alice321

Original post by Scarlette

1,1,1-trifluoro-2,2-dichloroethene
Less expensive as it doesn't contain chlorine or fluorine
Not used as a cleaner as it doesn't contain chlorine (a disinfectant)

no 1,1-dichloro-2,2,2-triflouroethene was right because you're supposed to do it alphabetically with c before f but they should allow both

Reply 790

AGrumpyMole

Original post by Alice321

no 1,1-dichloro-2,2,2-triflouroethene was right because you're supposed to do it alphabetically with c before f but they should allow both

it was ethane not ethene

Reply 791

swimming002

Guys lets all stop panicking! None of us can do anything about it now! I know its hard because its all you want to think about but for most of you this is your AS year, once you have done A level chemistry you will miss this topic and there are another 2 chances for you to retake! Just enjoy the summer :smile: