What do we need to know for M7 IQ5 Dot Point 4 (2 Viewers)

[Dzeeshr]

Hi all

See this dot point from the syllabus for Module 7 Reactions of organic acid and bases:



What do we actually have to know for this dot point??

What is it referring to and how could I be assessed on it?

I can't find any explicit info - if any of you could give some insight for what your teacher's taught regarding this, I would appreciate it

 

[Geniusly]

From what I remember:

Carboxylic acids are weak acids. The carbonyl group polarises the molecule, allowing the hydrogen atom of the hydroxyl group to be protonated.

Amines (Not Amides) are weak organic bases. The nitrogen atom has a free lone pair of electrons that it is able to donate in order to accept another hydrogen atom, making it a base.


Questions on this can be to explain why said organic acids and bases are acidic and basic. Explain the trends in acidity and basicity with increased carbon chain lengths. But also, I've seen a few that are just Mod 5/Mod 6 equilibrium questions using an organic acid or base instead.

 

[wizzkids]

What do we actually have to know for this dot point??

You don't have to know a great deal of depth on this specific syllabus point.
You should be able to apply the Brønsted-Lowry model of acids and bases to organic acids and bases. Be able to draw conclusions about the link between structure and physical properties like melting point, boiling point and solubility. Recognise that the basic nature of amines derives from the non-bonding electron pair on the nitrogen atom. Recognise the trend that solubility in non-polar solvents increases as chain length increases. Be able to recognise from the pKa values that organic acids are generally weak acids in aqueous solution, and organic bases are generally weak bases. Phenol (hydroxybenzene) is an example of a fairly strong organic acid (pKa =10) whilst ethylamine is an example of a fairly strong organic base (about 10 times more basic than ammonia solution).
That's an outline of what you need to know and apply.

 

[Dzeeshr]

You don't have to know a great deal of depth on this specific syllabus point.
You should be able to apply the Brønsted-Lowry model of acids and bases to organic acids and bases. Be able to draw conclusions about the link between structure and physical properties like melting point, boiling point and solubility. Recognise that the basic nature of amines derives from the non-boding electron pair on the nitrogen atom. Recognise the trend that solubility in non-polar solvents increases as chain length increases. Be able to recognise from the pKa values that organic acids are generally weak acids in aqueous solution, and organic bases are generally weak bases. Phenol (hydroxybenzene) is an example of a fairly strong organic acid (pKa =10) whilst ethylamine is an example of a fairly strong organic base (about 10 times more basic than ammonia solution).
That's an outline of what you need to know and apply.

Thanks so much! Thorough answers

 

[Ybot08]

From what I remember:

Carboxylic acids are weak acids. The carbonyl group polarises the molecule, allowing the hydrogen atom of the hydroxyl group to be protonated.

Amines (Not Amides) are weak organic bases. The nitrogen atom has a free lone pair of electrons that it is able to donate in order to accept another hydrogen atom, making it a base.


Questions on this can be to explain why said organic acids and bases are acidic and basic. Explain the trends in acidity and basicity with increased carbon chain lengths. But also, I've seen a few that are just Mod 5/Mod 6 equilibrium questions using an organic acid or base instead.

Some schools also require the knowledge that amides are very weakly basic due to their resonance structure, (and perhaps that even weaker are ketones etc)
and alcohols are very weak acids, some stronger ones such as phenol (benzene resonance structure which I think is barely in syllabus but this is an application I think is oos, but I’ve definitely seen stuff on phenol acidity)

These things are typically considered edge/out of syllabus and are very unlikely to be tested in hsc
I would check with the teacher first thing, because they know your internals, then research based on what they say