A gas with an initial temperature of 950 C undergoes the process shown in the figure .
What is the final temperature?(answer in k)
How many moles of gas are there?
http://session.masteringphysics.com/problemAsset/1...
thank uuuu in advance.....
1 Answer

Using the ideal gas law pV = nRT From your figure p = constant = 3atm and V1 =300cm^3
V2 = 100cm^3. If you take the ratio of condition 1 to 2 you get a relationship between the temperatures.
pV1 = nRT1 or nR = pV1/T1 for condition 2 nR = p*V2/T2 setting these equal
pV1/T1= pV2/T2 or T2 = T1*V2/V1 here T1 = 950+273 = 1223K And V2/V1 = 0.33333
So T2 = 1223/3 = 408K = 135degC
Now we can solve for n n = p*V/RT use either condition to get n = 3*1.013x10^5*300/10^6/(8.314*1223) = 8.97x10^3 mol