X is a dipeptide (when two monomers of amino acid join together). It is refluxed so that it can be hydrolysed to form 2 amino acid. HCL acts as a catalyst
Can someone please explain 15d for me please? June 2012. Need I say, Unit 5?
Looking at the summary for that reaction, I would say the answer is Potassium permanganate, in acid solution. I don't know where the mark scheme has got: "Sodium Hydroxide and a Manganese salt" from?
X is a dipeptide (when two monomers of amino acid join together). It is refluxed so that it can be hydrolysed to form 2 amino acid. HCL acts as a catalyst
Ohhh okay, thank you! I thought polypeptides were hydrolysed by dilute acid... hmmm. Can they be hydrolysed with alkali or not?
Do you know if that is the only method of separation that we'll need to know about? If not, do we still follow those steps for any separation or does it differ depending on the mixture we're trying to separate? My book doesn't mention any of this.
Hey sorry for late reply, basically, in the exam I am hoping they will give context, so it will be much easier to see what they want, but there are normally two methods of extraction, depending on whether it is stable or unstable. In the case of being unstable organic, you must use steam distillation, followed by the standard drying procedure i.e. run of aqueous layer and add anhydrous salts. Other wise, if its stable, you can just distill it off, or if you know it is far more soluble in a certain solvent, whereas other substances in the same solution won't be, then you can use solvent extraction. Hope this makes sense? x
Can someone please explain 15d for me please? June 2012. Need I say, Unit 5?
Looking at the summary for that reaction, I would say the answer is Potassium permanganate, in acid solution. I don't know where the mark scheme has got: "Sodium Hydroxide and a Manganese salt" from?
Thanks!
Basically, any manganese salt in solution will form a complex ion with water ligands. Then if you add sodium hydroxide or even ammonia (any base) it will deprotonate it to the corresponding manganese hydroxide for which its solid (neutral complex) form can be written as Mn(OH)2 or Mn(H20)4(OH)2
Basically, any manganese salt in solution will form a complex ion with water ligands. Then if you add sodium hydroxide or even ammonia (any base) it will deprotonate it to the corresponding manganese hydroxide for which its solid (neutral complex) form can be written as Mn(OH)2 or Mn(H20)4(OH)2
Hey sorry for late reply, basically, in the exam I am hoping they will give context, so it will be much easier to see what they want, but there are normally two methods of extraction, depending on whether it is stable or unstable. In the case of being unstable organic, you must use steam distillation, followed by the standard drying procedure i.e. run of aqueous layer and add anhydrous salts. Other wise, if its stable, you can just distill it off, or if you know it is far more soluble in a certain solvent, whereas other substances in the same solution won't be, then you can use solvent extraction. Hope this makes sense? x
thank you but i'm having a really hard time understanding this topic. my book mentions absolutely nothing on this. it tells me how to separate solids (recrystalisation) but not liquids. how does separation differ for aqueous and organic liquids? what is solvent extraction?