This apple is SO SWEET, but, This is SUCH a sweet APPLE.
SO and SUCH are used with THAT to give justification.
This apple is SO SWEET THAT I will have another one, but, This is SUCH a sweet APPLE THAT I will have another one.
SO can also be used with MUCH and MANY SO MUCH for NON COUNTABLE nouns, SO MANY for COUNTABLE nouns. SUCH MUCH and SUCH MANY don't exist.
There is SO MUCH PAINT (non countable) and there are SO MANY ANIMALS (countable).
To practice so & such with online activities: Agenda Web
To review the class Power Point on Su & Such: Power Point