Question

I am conducting my Physics 1 Ideal Gas Laws Lab and have no ideal what equations to use to solve these problems please help!!

1. Using the ideal gas law compute the number of moles of the gas present in the Gas Law apparatus The gas constant for air is 286.9 J/kg◦K or J/kg◦C. Then determine the molecular mass of the gas in the Gas Law apparatus?
2. We can determine the molecular mass of air by considering nitrogen (N2), oxygen (O2) and argon (Ar) make up 78%, 21% and 1% of the atmosphere. The atomic masses of nitrogen, oxygen and argon are 14, 16, 40 grams/mole. Compute the molecular mass of air.
3. What is the work done at each increment? What is the total work done in compressing its volume from 65 mL to 20 mL?

4. Given the previous pressure and volume along with the current volume, compute the predicted current pressure of the gas.

Answer 1

1. For the ideal gas , gas equation is

  

where P= pressure of the gas

V = volume of the gas

n= number of moles of the gas

R = gas constant

T= Temperature

from the gas law apparatus you measure pressure,volume,temperature, and the gas constant is given, put these values in above equation you can find the n(number of mole of the gas).

2. from the above you will find the number of mole of the air, using this you will find number of atoms in the air beacause 1mol= 6.022*10^23 atoms. Now in this number of atoms 78% , 21% ,1% are atoms of nitrogen,oxygen and argon respectively.multiply these number of atoms to there molecular mass and them all, this result is the mass of the gas.

3. work done = pressure* change in volume

  

4. at constant temperature

Where P1,V1 are previous pressure and volume, and P2,V2 are current pressure and volume.