[Ari Ben Canaan]

I know that you react chlorine in the presence of an AlCl3 catalyst and as a result you will get chlorobenzene.

My question is what STATE must the chlorine be in ? Should be in a gas an aqueous solution ?

[Doctor.]

(Original post by Ari Ben Canaan)
I know that you react chlorine in the presence of an AlCl3 catalyst and as a result you will get chlorobenzene.

My question is what STATE must the chlorine be in ? Should be in a gas an aqueous solution ?

Chlorine will have to be an electrophile in order to react with the Benzene? So yeah, if its one mark I would just say it will have to be an electrophile!

[Ari Ben Canaan]

(Original post by Doctor.)
Chlorine will have to be an electrophile in order to react with the Benzene? So yeah, if its one mark I would just say it will have to be an electrophile!

No, you misunderstood me. Does the chlorine have to be in a gaseous state for this reaction ?

Aqueous maybe ?

[Ari Ben Canaan]

bump

[Ari Ben Canaan]

(Original post by charco)
x

Could you take a look at this please ?

[StrangeCloud]

Chlorine must be a gas as an electrophile must be positive ( forms positive ion when reacts with AlCl3)

[Doctor.]

(Original post by StrangeCloud)
Chlorine must be a gas as an electrophile must be positive ( forms positive ion when reacts with AlCl3)

Cl+ + AlCl4-?

but why would it have to be a gas? Couldn't the reaction take place in a solution of AlCl3 and Cl2 is bubbled through?

[Hypocrism]

You add AlCl3 (an electron carrier) to get Cl+ and AlCl4-. Electrophile substitutes etc. It's a gas because that's Cl2 at room temperature.

[charco]

(Original post by Ari Ben Canaan)
Could you take a look at this please ?

Aluminium chloride is a Friedel-Crafts catalyst. This involves the electron pair from a chlorine molecule coordinating to the electron deficient aluminium in the trichloride. For this to happen the AlCl₃ must be molecular.

Remember that in the presence of water AlCl₃ gets hydrolysed to the aluminium hexaaqua ion (and HCl), so water cannot be present, i.e. anhydrous conditions are needed.

The chlorine is added (by bubbling through) to the aluminium chloride as a slurry in an inert solvent to form the intermediate complex [AlCl₄]^-Cl⁺.

This is then added to the benzene and refluxed.

[Ari Ben Canaan]

(Original post by charco)
Aluminium chloride is a Friedel-Crafts catalyst. This involves the electron pair from a chlorine molecule coordinating to the electron deficient aluminium in the trichloride. For this to happen the AlCl₃ must be molecular.

Remember that in the presence of water AlCl₃ gets hydrolysed to the aluminium hexaaqua ion (and HCl), so water cannot be present, i.e. anhydrous conditions are needed.

The chlorine is added (by bubbling through) to the aluminium chloride as a slurry in an inert solvent to form the intermediate complex [AlCl₄]^-Cl⁺.

This is then added to the benzene and refluxed.

I have another question. Lets say I want to react a mass of Li with water and collect the Hydrogen gas evolved with zero loss of Hydrogen gas.

Using common laboratory equipment how would I setup the experiment ?

[clownfish]

(Original post by Ari Ben Canaan)
I have another question. Lets say I want to react a mass of Li with water and collect the Hydrogen gas evolved with zero loss of Hydrogen gas.

Using common laboratory equipment how would I setup the experiment ?

You could have the lithium waiting in a two necked flask, place a rubber bung in one neck with an attachment to a gas syringe through the other neck, then use a needle to inject the water in through the rubber bung.

[charco]

(Original post by Ari Ben Canaan)
I have another question. Lets say I want to react a mass of Li with water and collect the Hydrogen gas evolved with zero loss of Hydrogen gas.

Using common laboratory equipment how would I setup the experiment ?

You could carefully float the lithium in a small (5ml) beaker (a bottletop or similar*) on a sample of water in a conical flask attached to a gas syringe. Make all of the connexions and shake the flask to mix the lithium and the water.

* I find that the plastic caps of the squeezy isotonic drinks bottles are perfect for this, but just use your imagination. It would be conceivable to use an origami boat made from greaseproof paper even...

[Ari Ben Canaan]

(Original post by charco)
You could carefully float the lithium in a small (5ml) beaker (a bottletop or similar*) on a sample of water in a conical flask attached to a gas syringe. Make all of the connexions and shake the flask to mix the lithium and the water.

* I find that the plastic caps of the squeezy isotonic drinks bottles are perfect for this, but just use your imagination. It would be conceivable to use an origami boat made from greaseproof paper even...

Excellent ! Thank you !!

One other question, why would you NOT use a conical flask when heating a sample of Calcium Carbonate so as to collect and measure some CO2 ?

Apparently this has something to do with the 'sharp' edges of a conical flask ?

[charco]

(Original post by Ari Ben Canaan)
Excellent ! Thank you !!

One other question, why would you NOT use a conical flask when heating a sample of Calcium Carbonate so as to collect and measure some CO2 ?

Apparently this has something to do with the 'sharp' edges of a conical flask ?

To decompose calcium carbonate requires far too much heat for a conical flask. The easiest thing to do is heat a pre-weighed crucible and calcium carbonate to constant mass, then subtract to obtain the mass difference.

[Ari Ben Canaan]

(Original post by charco)
To decompose calcium carbonate requires far too much heat for a conical flask. The easiest thing to do is heat a pre-weighed crucible and calcium carbonate to constant mass, then subtract to obtain the mass difference.

Yes, that makes sense.

I have another question.

CuCO₃.Cu(OH)₂.XH₂O

Consider the above compound.

Lets say I stick a three on the front.

3CuCO₃.Cu(OH)₂.XH₂O

Does this mean there will be 3X moles of water in this compound and 3 moles of Cu(OH)2 ?

[charco]

(Original post by Ari Ben Canaan)
Yes, that makes sense.

I have another question.

CuCO₃.Cu(OH)₂.XH₂O

Consider the above compound.

Lets say I stick a three on the front.

3CuCO₃.Cu(OH)₂.XH₂O

Does this mean there will be 3X moles of water in this compound and 3 moles of Cu(OH)2 ?

Integers that appear before a formula ONLY have relevance in an equation as a balancing coefficient.

They do not affect any part of the formula.

In your example the coefficient "3" means that there are 3 moles of the compound in the balanced equation. So, yes, it must multiply everything that follows it.

[Ari Ben Canaan]

Yup, a balanced equation is the situation I was referring to.

Thank you !