home / study / science / chemistry / chemistry questions and answers / The Ideal

Question

home / study / science / chemistry / chemistry questions and answers / The Ideal Gas Law , PV= NRT Can Be Used To Predict The Changes In Pressure, Temperature, And ...

Your question has been answered

Let us know if you got a helpful answer. Rate this answer

Question: The ideal gas law , PV= nRT can be used to predict the changes in Pressure, Temperature, and Volu...

The ideal gas law , PV= nRT can be used to predict the changes in Pressure, Temperature, and Volume. R = 82.06 cc-atm/deg-mol.

a. If you have a sealed core tube containing 21% O2, how many millimoles of O2 would that be if there was 500cm^3 of head space at 25 degrees celcius and 1 atm?

b. How would that change if the temperature of the tube was 85 degrees celcius?

Explanation / Answer

a) Use the equation PV = nRT to first calculate the total moles
   Pressure P = 1 atm
   Temperature = 25 C = 298 k
   Volume = 500 cm3.
   (1 atm)x(500 cm3) = n x (82.06 cm3-atm/deg K-mol)x(298 K)
   n = 0.02045 moles = 20.45 mmoles
Now O2 is 21 % therefore millimoles of O2 = (21/100) x 20.45
   = 4.2945 millimoles

b) Since the core tube is sealed the volume and the total moles will remain unchanged on increasing the temperature.
   Increasing temperature to 85 C will increase the presssure in the sealed core tube.
   The pressure when the temperature becomes 85 C or 358 K will be
Px(500 cm3) = (0.02045) x (82.06 cm3-atm/deg K-mol)x(358 K)
   P = 1.20 atm

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.