I had a chem topic test today for mod 7 organic chem and one of the questions was which of the following is most basic? CH3CH2COOH, CH3CH2OH, CH3CH2CONH2, or CH3CH2CH2NH2 (basically carboxylic acid vs alcohol vs amide vs amine). We haven't done mod 5 or 6 yet so I don't really know what constitutes as basic or acidic and how to determine it? Can anyone help? (answer was the amide I think or might've been the amine)
You have to know the acidic or basic properties of the organic compounds listed in the first section of Module 7, e.g. alcohols, amines, aldehydes, ketones, carboxylic acids, amides etc.
It's not really linked to the mod 5 or 6 like the other poster has commented. Yes to be able to answer other types of questions that are cross-module where they ask you about the theories and applying it to the organic compounds you will need to know mod 5 and 6.
However, this question doesn't ask those things. It's only testing if you have memorised what type of organic compounds are acids, bases or neutral.
For purposes of HSC:
- alcohols, aldehydes, ketones, alkanes, alkenes, alkynes = neutral
- carboxylic acids = acidic
- amines = basic
- amides = neutral
In this case knowing that although amides have an NH2 group like amines, the amide NH2 is neutral and the amine NH2 is basic.
The reason why is depicted below however this is outside of the scope of the HSC syllabus (I know as I have tutored chem for 5+ years and am doing a PhD in organic chemistry). Just for your general understanding you can see the image, however don't worry about being able to write a response in an exam explaining the reasons why since this is not a topic covered in HSC.
The image above in simple words is saying, the NH2 in an amide can't be removed easily because the C=O group changes it's base properties compared to just having an NH2 in an amine
