Answer :
Anesthetic in dentistry consists of a mixture of dinitrogen oxide (N₂O) and oxygen gas (O₂), which is administered through an inhaler over the nose. Total pressure of the mixture ([tex]P_{total}[/tex]) is sum of partial pressure of N₂O ([tex]p_{N_{2}O }[/tex]) and partial pressure of O₂, ([tex]p_{O_{2} }[/tex]).
[tex]P_{total}=p_{N_{2}O } + p_{O_{2} }[/tex]
[tex]P_{total}= 740 mmHg, p_{O_{2} }[/tex]=370 mmHg
So, [tex]p_{N_{2}O }[/tex]= (740-370) mmHg= 370 mmHg=370 torr
Hence, partial pressure of N₂O is 370 torr.
As, 1mmHg= 1 torr.