Edexcel A2 Chemistry Unit 4 26/01/12 PM

SAMMYBACON whether its E or Z, its bromobut-3-ene cause theres an additional carbon atom.

Reply 782

robert jones that sounds reasonable and I'm hoping its true cause I think I'll get 83!

Reply 783

Original post by farhanyen

SAMMYBACON whether its E or Z, its bromobut-3-ene cause theres an additional carbon atom.

Lol no

Reply 784

GleekyTime-Lord

Ergh made some dumb mistakes in the MCQ *sigh*

And yeah, it said why would you use 250 instead, meaning that even though you u get a better yield for smaller temp, its better to use a higher temp otherwise the reaction woud be too slow. So its faster rate.

Btw guys for the last question, did you guys use this equation and explain it:

HIn (reversible arrow) H+ + In-

Reply 785

Original post by GleekyTime-Lord

Ergh made some dumb mistakes in the MCQ *sigh*

And yeah, it said why would you use 250 instead, meaning that even though you u get a better yield for smaller temp, its better to use a higher temp otherwise the reaction woud be too slow. So its faster rate.

Btw guys for the last question, did you guys use this equation and explain it:

HIn (reversible arrow) H+ + In-

Nope I gave an example :smile:

Like Diluting it by a factor of 10

OP

Effkay, so what did you write for the EZ qs

Reply 788

Original post by farhanyen

Effkay, so what did you write for the EZ qs

The z isomer one.
E is definately wrong

Reply 789

How about the purification technique for aldehyde? Is it distillation?

Reply 790

MrAdamBakewell

Original post by EffKayy

Nope I gave an example :smile:

Like Diluting it by a factor of 10

Unfortunately, your manifestation of diluting the acid is wrong as diluting a WEAK ACID by a factor of 10 infact only increases pH by 0.5 :rolleyes:

Reply 791

I meant did you write bromo-2-ene or bromo-3-ene what did you mean by "lol no"

Reply 792

Original post by MrAdamBakewell

Unfortunately, your manifestation of diluting the acid is wrong as diluting a WEAK ACID by a factor of 10 infact only increases pH by 0.5 :rolleyes:

Ph still increases though...?

Reply 793

Original post by farhanyen

How about the purification technique for aldehyde? Is it distillation?

Wrong. Recrystallisation

Reply 794

vishreyp

Original post by farhanyen

How about the purification technique for aldehyde? Is it distillation?

recrsytallisation

Reply 795

why not distillation?

Reply 796

Besides, I explained my point fully for the last one, example just backed my point of the ph increasing

Reply 797

recrystallisation is for solid products!

Reply 798

sik

what did you guys write for the prevention and cause question for transesterification

Reply 799