Answer:
40 mmHg
Step-by-step explanation:
Dalton's Law of Partial Pressures, states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture. Hence if I have gases A,B and C and I choose to designate the pressure of gas A as PA, the pressure of gas B as PB , the pressure of gas C as PC and the total pressure of all the gases together as PT. Then from Dalton's law; PT= PA + PB + PC
From the question; we designate the pressure of hydrogen as PA, pressure of nitrogen as PB and pressure of oxygen as PC.
PA= 70 mmHg
PB= the unknown
PC= 650 mmHg
If the total pressure of the gas mixture (PT) = 760 mmHg
Then;
760= 70 + PB + 650
PB= 760- (70+650)
PB= 760 - 720
PB= 40 mmHg
Therefore, the partial pressure of nitrogen is 40 mmHg