Organic chemistry and Organic substance

Organic chemistry noun - The chemistry of compounds containing carbon (originally defined as the chemistry of substances produced by living organisms but now extended to substances synthesized artificially).

Organic substance and organic chemistry are semantically related. In some cases you can use "Organic substance" instead a noun phrase "Organic chemistry".

Organic chemistry and organic substance are semantically related. You can use "Organic chemistry" instead a noun "Organic substance".