Chemical Reaction Engineering Questions and Answers – Stoichiometry – Constant – Volume Batch Reaction Systems


This set of Chemical Reaction Engineering Assessment Questions and Answers focuses on “Stoichiometry – Constant – Volume Batch Reaction Systems”.

1. State true or false.
Constant volume system means that the volume of reactor is constant.
a) True
b) False
View Answer

Answer: b
Explanation: The volume of the reaction mixture remains constant for a constant volume system. The system is incompressible.

2. Which of the following represents constant volume system?
a) C + O2 → CO2
b) CO + H2O → CO2 + H2
c) N2 + 3H2 → 2NH3
d) SO2 + 0.5O2 → SO3
View Answer

Answer: b
Explanation: Gas phase reactions in which the number of moles of the product is equal to the number of moles of reactant is a constant volume system. In CO + H2O → CO2 + H2, 2 moles of reactants form 2 moles of product.

3. What is the partial pressure of the product related to the total pressure for a constant volume system? (Where pR is the partial pressure of the product, pR0 is the initial partial pressure of the product, P is the total pressure, P0 is the initial pressure of reaction mixture, r is the stoichiometry of the product and ∆n is the difference between the number of moles of the product and the number of moles of the reactant)
a) pR = \(\frac{r}{∆n}\) (P – P0)
b) pR = pR0 – \(\frac{r}{∆n}\) (P – P0)
c) pR = pR0 + (P – P0)
d) pR = pR0 + \(\frac{r}{∆n}\) (P – P0)
View Answer

Answer: d
Explanation: For the reaction, aA + bB → rR + sS, pR = CRRT. CR is the product concentration. CRRT = pR0 + \(\frac{r}{∆n}\) (P – P0).

4. The desired relationship between the partial pressure of reactant and total pressure for the reaction N2O4 → 2NO2 is _____
a) PA = PA0 – 2(P – P0)
b) PA = 2PA0 – (P – P0)
c) PA = PA0 – (P – P0)
d) PA = PA0 + (P – P0)
View Answer

Answer: c
Explanation: ∆n = 2-1 =1. pA = pA0 – \(\frac{a}{∆n}\) (P – P0), a is the stoichiometry of the reactant. Hence, PA = PA0 – (P – P0).

5. If the total pressure for reaction is initially is 2 atm and the pressure is changed to 3 atm for the reaction to occur, then the value of (PA – PA0) for the reaction N2O → N2 + 0.5O2 is ____
a) -2
b) 2
c) -1
d) 1
View Answer

Answer: a
Explanation: ∆n = 0.5
pA = pA0 – \(\frac{a}{∆n}\) (P – P0)
(PA = PA0) = \(\frac{-1}{0.5}\)(3-2)
(PA = PA0) = -2.

Sanfoundry Global Education & Learning Series – Chemical Reaction Engineering.

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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