Answer : The molar mass of unknown substance is, 39.7 g/mol
Explanation : Given,
Mass of unknown substance = 9.56 g
Volume of solution = 100.0 mL
Molarity = 2.41 M
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :

Now put all the given values in this formula, we get:


Therefore, the molar mass of unknown substance is, 39.7 g/mol
Answer:
a). P = 688 atm
b). P = 1083.04 atm
c).Δ G = 16.188 J/mol
Explanation:
a). Fugacity 'f' can be calculated from the following equations :

where, P = pressure , Z = compressibility
Now, the virial equation is :
........(1)
Also, PV=ZRT for real gases .......(2)
∴ 

So from the fugacity equation ,




Putting the value of P = 500 atm in the above equation, we get,
f = 688 atm
b). Given f = 2P



∴ P = 1083.04 atm
c). dG = Vdp -S dt at constant temperature, dT = 0
Therefore, dG = V dp



![$\Delta G=R[\ln\frac{P_2}{P_1}+6.4 \times 10^{-4}(P_2-P_1)]$](https://tex.z-dn.net/?f=%24%5CDelta%20G%3DR%5B%5Cln%5Cfrac%7BP_2%7D%7BP_1%7D%2B6.4%20%5Ctimes%2010%5E%7B-4%7D%28P_2-P_1%29%5D%24)
![$\Delta G=8.314\times 298[\ln\frac{500}{1}+6.4 \times 10^{-4}(500-1)]$](https://tex.z-dn.net/?f=%24%5CDelta%20G%3D8.314%5Ctimes%20298%5B%5Cln%5Cfrac%7B500%7D%7B1%7D%2B6.4%20%5Ctimes%2010%5E%7B-4%7D%28500-1%29%5D%24)
Δ G = 16.188 J/mol
Charles law states that there is a directly proportional relationship between the volume and the temperature of the gas at certain pressure.
Therefore,
V1/T1 = V2/T2
V1 is unknown
T1 = 159K
V2 = 15.5m3
T2 = 456K
V1/159 = 15.5/456
V1 = (15.5*159)/456 = 5.404m3.
When the volume of a gas is changed from 5.404 m3 to 15.5 m3 the temperature will change from 159 K to 456 K.