Answer: The partial pressure of nitrogen gas if the total pressure is 111.7 atm is 88.243 atm.
Explanation:
Given: Mole fraction of oxygen = 0.21
Total pressure = 111.7 atm
It is known that the sum of moles fractions is always equal to 1. So, mole fraction of nitrogen is calculated as follows.
Mole fraction of nitrogen + mole fraction of oxygen = 1
Mole fraction of nitrogen = 1 - mole fraction of oxygen
Mole fraction of nitrogen = 1 - 0.21
Mole fraction of nitrogen = 0.79
Now, formula used to calculate the partial pressure of nitrogen is as follows.
[tex]P_{N} = X_{N} \times P_{total}[/tex]
where,
[tex]P_{N}[/tex] = partial pressure of nitrogen
[tex]X_{N}[/tex] = mole fraction of nitrogen
[tex]P_{total}[/tex] = total pressure
Substitute the values into above formula as follows.
[tex]P_{N} = X_{N} \times P_{total}\\= 0.79 \times 111.7 atm\\= 88.243 atm[/tex]
Thus, we can conclude that the partial pressure of nitrogen gas if the total pressure is 111.7 atm is 88.243 atm.