Thermodynamics Questions and Answers – Equations of State

«
»

This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on “Equations of State”.

1. For the ideal gas equation, what assumptions are made?
a) there is little or no attraction between the molecules of the gas
b) the volume occupied by the molecules is negligibly small compared to the volume of the gas
c) both of the mentioned
d) none of the mentioned
View Answer

Answer: c
Explanation: The ideal gas equation pv=RT is established from the postulates of the kinetic theory of gases considering these two assumptions.
advertisement

2. When does a real gas obey the ideal gas equation closely?
a) at high pressure and low temperature
b) at low pressure and high temperature
c) at low pressure and temperature
d) at high pressure and temperature
View Answer

Answer: b
Explanation: At low pressure and high temperature, the intermolecular attraction and the volume of the molecules compared to the total volume of the gas are not of much significance.

3. The real gases deviate from the ideal gas equation when the pressure increases.
a) true
b) false
View Answer

Answer: a
Explanation: With increase in pressure, the intermolecular forces of attraction and repulsion increase, and also the volume of the molecules becomes appreciable compared to the gas volume.
advertisement
advertisement

4. The corrected gas equation is given by
a) (p+a/(v2))(v+b)=RT
b) (p-a/(v2))(v-b)=RT
c) (p-a/(v2))(v+b)=RT
d) (p+a/(v2))(v-b)=RT
View Answer

Answer: d
Explanation: The two correction terms were introduced by van der Waals.

5. Which of the following statement is true about the correction terms?
a) the coefficient a was introduced to account for the existence of mutual attraction between the molecules
b) the term a/(v2) is called the force of cohesion
c) the coefficient b was introduced to account for the volumes of the molecules and is known as co-volume
d) all of the mentioned
View Answer

Answer: d
Explanation: These coefficients were also introduced by van der Waals.
advertisement

6. Real gases conform more closely with the van der Waals equation of state than the ideal gas equation of state.
a) true
b) false
View Answer

Answer: a
Explanation: This happens particularly at higher pressures.

7. The following also gave two-constant equations of state.
a) Berthelot
b) Dieterici
c) Redlich-Kwong
d) all of the mentioned
View Answer

Answer: d
Explanation: These are also two-constant equations of state other than the van der Waals equation.
advertisement

8. Compressibility factor Z is given by
a) RT/pv
b) pv/RT
c) (RT/pv)2
d) (pv/RT)2
View Answer

Answer: b
Explanation: This ratio is known as compressibility factor.

9. For an ideal gas, Z has the value
a) 0
b) 2
c) 1
d) infinity
View Answer

Answer: c
Explanation: For an ideal gas, pv=RT hence Z=1.
advertisement

10. The magnitude of Z at a particular pressure and temperature indicates the extent of deviation of the gas from the ideal gas behaviour.
a) true
b) false
View Answer

Answer: a
Explanation: This is a basic fact about the compressibility factor.

Sanfoundry Global Education & Learning Series – Thermodynamics.
To practice all areas of Thermodynamics, here is complete set of 1000+ Multiple Choice Questions and Answers.

Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

advertisement
advertisement
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn | Youtube | Instagram | Facebook | Twitter