Engineering Questions with Answers - Multiple Choice Questions
Separation Processes MCQ’s – Non-ideal Thermodynamic Property Models
1 - Question
What is the p-v-T equation of state?
a) Relationship between volume and temperature
b) Relationship between pressure, molar volume and temperature
c) Relationship between pressure and temperature
d) Relationship between pressure and molar volume
View Answer
Explanation: The Relationship between pressure, molar volume and temperature is the p-v-T equation of state.
2 - Question
What does the ideal gas equation neglects?
a) Temperature of molecules
b) Friction between molecules
c) Volume occupied by the molecules
d) Pressure occupied by the molecules
View Answer
Explanation: The ideal gas equation neglects the volume occupied by the molecules hence it is only applicable at low pressures.
3 - Question
What is the van der waal’s equation of non-ideal gas?
a) [P + a(n/v)2](v/n –b) =RT
b) [P + a(n/v)2] =RT
c) [P + (n/v)2](v/n –b) =RT
d) [P + a(n/v)2](v/n ) =RT
View Answer
Explanation: [P + a(n/v)2](v/n –b) =RT is the correct equation for real gases.
4 - Question
What is the formula for acentric factor?
a) Z = (-log(Ps/Pc)Tr=o.7) – 1000
b) z = (-log(Ps/Pc)Tr=o.7) – 1.000
c) ω = (-log(Ps/)Tr=o.7) – 1.000
d) ω = (-log(Ps/Pc)Tr=o.7) – 1.000
View Answer
Explanation: ω = (-log(Ps/Pc)Tr=o.7) – 1.000 is the correct equation for determining acentric factor based on the law of corresponding states.
5 - Question
What is the value of ω for symmetric molecules?
a) 1
b) 0.264
c) 0
d) 0.490
View Answer
Explanation: The value of ω is 0 for symmetric molecules.
6 - Question
How can the compressibility factor be determined form generalized equation and Redich-kwong equation?
a) Z3 – Z2 + (A-B-B2)Z – AB =0
b) Z3 – Z2 + (A-B-B2) – AB =0
c) Z3 – Z2 + (A-B-B2)Z – A =0
d) Z3 – Z2 + (A-B)Z – AB =0
View Answer
Explanation: The generalized equation PV= ZRT and the redich kwong equation are combined to give Z3 – Z2 + (A-B-B2)Z – AB =0 where A and B are constants which can be determined.
7 - Question
If A =0.2724 and B= 0.05326 find the value of compressibility factor Z.
a) 0.7867
b) 0.7314
c) 0.8656
d) 10.435
View Answer
Explanation: Z3 – Z2 + (A-B-B2)Z – AB =0 is the equation used. Hence by solving Z3 – Z2 + (0.2724-0.05326-0.053262)Z – 0.2724*0.05326 =0 we get Z= 0.7314.
8 - Question
What is the correct representation of Soave-Redich-Kwong equation?
a) P = [RT/v-b] – [a/v2+bv+a].
b) P = [RT/v-b] – [a/v2+bv].
c) P = [RT/v-b] – [a/v2+bv+b].
d) P = [RT/v-b] – [a/v2].
View Answer
Explanation: P = [RT/v-b] – [a/v2+bv] is the Soave-Redich-Kwong equation.
9 - Question
What is the value of b if the temperature is 477.6K and the saturation pressure is 2829kPa?
a) 836.7 units
b) 2334.666 units
c) 0.0626 units
d) 0.4356 units
View Answer
Explanation: b = 0.08664RT/Pc is the equation is used to determine b. Hence b= 0.08664 *8.314*477.6/2829000= 2334.666 units
10 - Question
If the critical temperature of propane is 369.8K and temperature of mixture is 477.6K and the saturation pressure is 4250kPa , what is the value of a?
a) 234.5 units
b) 678.9 units
c) 765.6 units
d) 836.7 units
View Answer
Explanation: a= 0.42748R2Tc2.5/PcT0.5 is the equation used to calculate a. Hence a= 0.427(8.314)2(369.8)2.5/4250000*(477.6)0.5.