Organic pathways

[destain]

From chloroethane to ethanamine
What reagent and what catalyst is needed?

and also just an additional question, how are you maent to find the base peak in mass spec?
and how is mass spec used to confirm the presence of OH and COOH in organic compounds..

[charmanderp]

The reagent would be ammonia gas. A strong base would be required as a catalyst, such as NaOH or KOH.

The base peak is the most stable part of a molecule. There's no real way to deduce what would form the base peak without a mass spectrum of m/e value but generally the most polar part of a molecule would, for example COOH+ in ethanoic acid.

If you knew the molecular formula of a molecule significant peaks at m/e values of 45 or 31 or 17 could confirm that there's a COOH group present or a CH2OH group or OH group.

[destain]

Would we ever be required to find the base peak...theres a question in Stav 2008?

And also cyclohexan-1,4-ol
Wouldn't that only have 3 carbon enviroments, looks pretty symmetrical to me...

[charmanderp]

I doubt that VCAA will ask you to find the base peak.

I think it would have 2 carbon environments, actually. 3 hydrogen environments though. And it would be called cyclohexan-1,4-diol.

[destain]

How come?
and oh ok maybe i dunno, im jsut copying the name from this paper...
OOOOOOOOOOOOO...is it because the 4 Cs are in one enviroment and the 2 that are attached to the OH are another?


and

1M solutions of several salts are prepared.
Which of the following salts produces the solution with the highest pH
a)Na2CO3
b)NaNO3
c)NH4CL
d)Na2SO4

[AllAboutTheLGs]

The reagent would be ammonia gas. No catalyst is required for the same reason that no catalyst would be required to convert chloroethane to ethanol.

The base peak is the most stable part of a molecule. There's no real way to deduce what would form the base peak without a mass spectrum of m/e value but generally the most polar part of a molecule would, for example COOH+ in ethanoic acid.

If you knew the molecular formula of a molecule significant peaks at m/e values of 45 or 31 or 17 could confirm that there's a COOH group present or a CH2OH group or OH group.

For chloroethane ->ethanamine don't you need to add a strong base such as NaOH?

[mihir94]

No, you add NH₃. You use NaOH if you want chloroalkane to alkanol.

[charmanderp]

How come?
and oh ok maybe i dunno, im jsut copying the name from this paper...
OOOOOOOOOOOOO...is it because the 4 Cs are in one enviroment and the 2 that are attached to the OH are another?


and

1M solutions of several salts are prepared.
Which of the following salts produces the solution with the highest pH
a)Na2CO3
b)NaNO3
c)NH4CL
d)Na2SO4

Sodium carbonate is basic so it would have the highest pH.

The reagent would be ammonia gas. No catalyst is required for the same reason that no catalyst would be required to convert chloroethane to ethanol.

The base peak is the most stable part of a molecule. There's no real way to deduce what would form the base peak without a mass spectrum of m/e value but generally the most polar part of a molecule would, for example COOH+ in ethanoic acid.

If you knew the molecular formula of a molecule significant peaks at m/e values of 45 or 31 or 17 could confirm that there's a COOH group present or a CH2OH group or OH group.

For chloroethane ->ethanamine don't you need to add a strong base such as NaOH?

Yeah you're right, actually. My bad.

[mihir94]

So when do you use NH₃?

[charmanderp]

You do use NH3, in the presence of a basic catalyst.

[mihir94]

Ohhh I see. Thanks

[stephanieteddy]

How come?
and oh ok maybe i dunno, im jsut copying the name from this paper...
OOOOOOOOOOOOO...is it because the 4 Cs are in one enviroment and the 2 that are attached to the OH are another?


and

1M solutions of several salts are prepared.
Which of the following salts produces the solution with the highest pH
a)Na2CO3
b)NaNO3
c)NH4CL
d)Na2SO4

Yeah you're right! The 4 carbons in the 'middle' are all in the same environment. One way I like figuring it out is to describe what's going on with each of the carbons. For example, This is a carbon attached to a CH attached to a COH. If you do that for all 4 C's in the middle you will find they all have the same description!

[destain]

oh so for that reaction you need a NaOH catalyst and a NH3 reagent?

And isnt NH4CL basic>

[charmanderp]

It ionises to form NH4+ and Cl-. NH4+ is ammonium which is an acid.

[destain]

can someone PLEASE give me a definite answer on this, im so confused...

If the question is....

Draw asparagine in a solution with ph2
(therefore acidic)
you WOULD ionise the Z group and make NH2 become NH3

HOWEVER...

if it said in WATER...(therefore a zwitterion?)
then would you or would you NOT ionise the NH2?