[swimming002]

(Original post by Princess Kawaii)
I don't know this...Can anyone explain please?

all i know is that its an ionic substance with a low enough melting point that is a liquid at room temperature - sorry i can't help more!

[swimming002]

(Original post by mortaz786)
WTF????

my thoughts exactly! I've never seen a question on it and it says it in page 52 of the revision guide we should know the diagrams?!

[cli121]

(Original post by Princess Kawaii)
I don't know this...Can anyone explain please?

An ionic liquid is an ionic compound with a low melting point.
it is used in friedal-crafts because: it allows reactions to be performed at lower temperatures, saving fuel as well as reducing pollution

[Cleoleo]

Could someone tell me what refluxing is and why it's good please?

[icedragon]

(Original post by Hazel247)
Does anyone understand what an Ionic liquid is? And why it's used in the Friedel Crafts reactions?

(Original post by Princess Kawaii)
I don't know this...Can anyone explain please?

From my revision guide they are ionic compounds with relatively low melting points - usually less than 100C. Sometimes the melting point is so low they're liquid at room temperature. They're desirable in industrial reactions over organic solvents because they are less volatile, less flammable, often less toxic, and they are easier to re-use and so reduce waste. Friedel-Crafts can be performed with them by adding AlCl3 to form a catalyst-solvent system which means the reactions can be performed at lower temperatures than with normal solvents, saving energy.

Apparently, anyway...

[mortaz786]

(Original post by Cleoleo)
Could someone tell me what refluxing is and why it's good please?

im sure this is f334..... it never comes up in f335 papers... only experimental teqnique is gal-liquid chromotography.

but anyway its heating something in a tube attatched to a vertical condensor then heat gently to oxidise?

not a good definition but I havent revised it in ages

[icedragon]

(Original post by Princess Kawaii)
I don't understand the last point. Can u/anyone explain it?

I thought that in the new model the bonds are of equal length which is the length inbetween the length of single bonds and double bonds

Single bonds are longer in length than double bonds. The Kekule structure proposed benzene contained double and single bonds alternating. If this was the case, benzene would have to have different bond lengths between the carbon atoms, but it doesn't, which is why the Kekule structure did not account for it.

[Cleoleo]

(Original post by mortaz786)
im sure this is f334..... it never comes up in f335 papers... only experimental teqnique is gal-liquid chromotography.

but anyway its heating something in a tube attatched to a vertical condensor then heat gently to oxidise?

not a good definition but I havent revised it in ages

a past paper q has asked about drawing the reflux apparatus...

[avataraang]

(Original post by mortaz786)
im sure this is f334..... it never comes up in f335 papers... only experimental teqnique is gal-liquid chromotography.

but anyway its heating something in a tube attatched to a vertical condensor then heat gently to oxidise?

not a good definition but I havent revised it in ages

Refluxing is good because it prevents the loss of reactants that are highly flammable and volatile, ensures a high yield of product.

[Anthony Soprano]

(Original post by Cleoleo)
Could someone tell me what refluxing is and why it's good please?

Reflux means heating strongly but in a an enclosed system where none of the reactants evaporate away. If that happened you would have a dry flask by the end.

[Cleoleo]

guys, if something doesn't dissolve in water, is it basically because more energy is required to break the water bonds than the energy released when bonds are made??

(does it include breaking the dipole bonds in the substance too or just water?? )

[Waki]

In a compound must the redox state be balanced all the time?

What i mean is for example 2CuF2 is -2 +2
will it always equal to 0 or can it be diffrent?

[cli121]

(Original post by mortaz786)
WTF????

all you need to know is:
amine group enables dye molecule to form hydrogen bonds with fibre molecules such as cotton, rayon and linen because they contain lots of OH groups, however these are not very colour fast because the hydrogen bonds are not very strong.

carboxylic acid/sulfonic acid help dye attach to -NH- links found in wool and silk. H+ ions move from dye to fibre forming ionic interaction. Better colourfastness.

SO3-Na+ can be added to make the dye more soluble as water dissolves ionic substances.

hope this helps?

[nazgul60]

can someone tell me OCRs definition of a nucleophile?

[Princess Kawaii]

(Original post by icedragon)
From my revision guide they are ionic compounds with relatively low melting points - usually less than 100C. Sometimes the melting point is so low they're liquid at room temperature. They're desirable in industrial reactions over organic solvents because they are less volatile, less flammable, often less toxic, and they are easier to re-use and so reduce waste. Friedel-Crafts can be performed with them by adding AlCl3 to form a catalyst-solvent system which means the reactions can be performed at lower temperatures than with normal solvents, saving energy.

Apparently, anyway...

Thanks!! which revision guide is this from?

[moodychopin]

(Original post by cli121)
all you need to know is:
amine group enables dye molecule to form hydrogen bonds with fibre molecules such as cotton, rayon and linen because they contain lots of OH groups, however these are not very colour fast because the hydrogen bonds are not very strong.

carboxylic acid/sulfonic acid help dye attach to -NH- links found in wool and silk. H+ ions move from dye to fibre forming ionic interaction. Better colourfastness.

SO3-Na+ can be added to make the dye more soluble as water dissolves ionic substances.

hope this helps?

Also the thing about fast reactive dyes forming strong covalent bonds with a fibre because they react with -OH or -NH groups! I think...

[nazgul60]

And do we need to know the experiments just like the previous module F334?

[icedragon]

(Original post by Princess Kawaii)
Thanks!! which revision guide is this from?

No problem . The CGP A2 Chemistry OCR B one.

[cli121]

(Original post by moodychopin)
Also the thing about fast reactive dyes forming strong covalent bonds with a fibre because they react with -OH or -NH groups! I think...

oh yeah! they're the most permanant type of dye mainly due to the ability to form covalent bonds

[Iepnauy]

(Original post by Bi0logical)
firstly in acids we can assume that the concentration of acid at equilibrium is equal to the concentration of acid initially.
Another assumption is that for every mole of H+ , there is of A-

in buffers:
- all the A- have come from the salt (contribution from the acid is negligible)
- the concentration of the acid in HA is the same as the amount of acid put into the solution.

Are these two points I've bolded basically the same?