Answer:
8.9 mg/l
Explanation: Temp doesnt matter so throw that out automatically then your equation is;
S1/P1=S2/P2
We are looking for S2 and that equation is;
S2=S1*P2/P1 and that is S2=22.25*1/2.5
A little bit of simple math and you get your answer: 8.9 mg/l
Pulmonary ventilation, and carbonic acid-bicarbonate buffering system
Answer: Total pressure inside of a vessel is 0.908 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual partial pressures. exerted by each gas alone.

= partial pressure of nitrogen = 0.256 atm
= partial pressure of helium = 203 mm Hg = 0.267 atm (760mmHg=1atm)
= partial pressure of hydrogen =39.0 kPa = 0.385 atm (1kPa=0.00987 atm)
Thus 
=0.256atm+0.267atm+0.385atm =0.908atm
Thus total pressure (in atm) inside of a vessel is 0.908