Chemical Engineering

Equations of State

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is not the equation of state?
Van der Waals Equation
Charles Equation
Holborn Equation
Peng Robinson Equation
Explanation:
Charles equation is simply P α 1/V which is not the equation of state.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Virial Equation is a ______
Arithmetic Progression
Geometric Progression
Harmonic Progression
None of the mentioned
Explanation:
Virial equation is PV = RT (1 + 1/V + 1/V2 + 1/V3 + – – – – -), which is a geometric progression.
Question 3
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Pass Ratio : 100%
A container is filled with a gas at 10 atm with molar volume 1 liter/mole, if B = – 0.053 liter/mole, C = 0.0026 liter2/mole2, what is the temperature of gas? (Use virial equation, neglect higher terms)
128.2 K
156.9 K
198.5 K
243.6 K
Explanation:
PV = RT(1 + B/V + C/V2), => T = 10*1/[0.0821*(1 – 0.053/1 + 0.0026/12)] = 128.2 K.
Question 4
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Pass Ratio : 100%
What is the pressure of CO2 at 0oC, molar volume = 4 liter/mole, if B = – 0.053 liter/mole, C = 0.0026 liter2/mole2? (Use virial equation, neglect higher terms)
2.4 atm
4.1 atm
5.5 atm
6.9 atm
Explanation:
pV = RT(1 + B/V + C/V2), => p = (0.0821*273/4)(1 – 0.053/4 + 0.0026/16) = 5.5 atm.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What is the unit of λ in the SRK equation?
Liter/mole
Mole/Liter
Atm(liter/mole)
It is dimensionless
Explanation:
In the SRK equation, λ is a dimensionless function of reduced temperature.
Question 6
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Pass Ratio : 100%
A container has O2 at 5 atm and molar volume 2 liter/mole, if a = 9.24 atm(liter/mole), b = 0.0907 liter/mole, what is the temperature of O2? (Use vander waal equation)
140 K
150 K
170 K
190 K
Explanation:
(p + a/V2)(V – b) = RT, => T = (5 + 9.24/22)(2 – 0.0907)/0.0821 = 170 K.
Question 7
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Pass Ratio : 100%
If the vander waal equation has only one root, what is the relation between a and b?
729a = pb2
243a = pb2
81a = pb2
9a = pb2
Explanation:
Vander waal equation, V3 – (nb + nRT/p)V2 + (n2a/p)V – n3ab/p = 0, comparing with (V – Vc)3 = 0, => 3n(a/p)1/2 = n(ab/p)1/3, => 729a = pb2.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What is the unit of ‘b’ in Peng Robinson equation?
Liter/mole
Liter2/mole2
Mole/Liter
Mole2/Liter2
Explanation:
Peng Robinson equation is p = RT/(V – b) – aα/[V(V + b) + b(V – b)], => unit of b = unit of molar volume = liter/mole.
Question 9
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Pass Ratio : 100%
What is the unit of ‘a’ in RK equation?
Liter/mole
Atm(liter/mole)
Atm(liter/mole)K0.5
Atm(liter/mole)K
Explanation:
RK equation is p = RT/(V – b) – a/[T0.5V(V + b)], => unit of a = atm(liter/mole)K0.5.
Question 10
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Pass Ratio : 100%
A container has H2 at 27oC and molar volume 1 liter/mole, if a = 9.24 atm(liter/mole), b = 0.0907 liter/mole, what is the temperature of H2? (Use vander waal equation)
7.5 atm
12.4 atm
15.6 atm
17.8 atm
Explanation:
(p + a/V2)(V – b) = RT, => p = 0.0821*300/(1 – 0.0907) – 9.24/12 = 17.8 atm.