Question

Should we always convert units of temp. and pressure while using the gases' laws?? like when we are using (P1V1=P2V2) can we just substitute the unit of P in kpa or in mmHg

Answer 1

As always, you should use what works, and is most convenient.

Explanation:

Old Boyle's Law ASSUMED constant temperature...and so `Pprop1/V`...and further that `P_1V_1=P_2V_2`...and given this proportionality we could use `"pints, litres, hogsheads, cubic metres"` PROVIDED that we used them on both sides of the equation. And the same applies for the units of pressure...`"atmospheres, kPa, foot pounds"`, would be acceptable if used consistently.

And I am sorry if I have not definitively answered your question.