Instruct in

Hi

Could you please tell me if the red part below sounds fully natural to your native ears?

Context: School Science Laboratory

It's my sentence.

The teacher instructed the students in how to use different chemicals. [Or instructed the students on how to use]

I did a bit of homework and found both instruct in and instruct on in use.

Thanks,

Tom

I would probably say "The teacher instructed the students in the use of different chemicals" or "The teacher gave the students instructions on how to use different chemicals," but there are various valid options. In your sentence I'd probably use "on."

Theoretically:
The teacher instructed the students in [= within the subject of] how to use different chemicals.
The teacher instructed the students on [= upon the subject of] how to use different chemicals.

The "in" and "on" versions used to be more of less equally popular, but since about 1972, the "on" version has become dominant and the "in" version seems little old fashioned.