Chemical Engineering Questions and Answers for experienced on “Material Balances for Batch and Semi-Batch Processes”.
1. A batch process is that in which material enters the system and _____ which of the following should fill the gap?
a) Leaves
b) Does not leaves
c) Half of it leaves
d) None of the mentioned
Answer: a
Clarification: A batch process is that in which material enters the system and operated and leaves.
2. A semi-batch process is that in which material enters the system and _____ which of the following should fill the gap?
a) Leaves
b) Does not leaves
c) Half of it leaves
d) None of the mentioned
Answer: b
Clarification: A semi-batch process is that in which material enters a system and does not leave.
3. A semi-batch process differs from an open process in which of the following?
a) Input
b) Output
c) Generation
d) Consumption
Answer: b
Clarification: A semi-batch process does not have output, while an open system has output.
4. A semi-batch process differs from a closed process in which of the following?
a) Input
b) Output
c) Generation
d) Consumption
Answer: a
Clarification: A semi-batch process has some input, while a closed process does not have input.
5. Tap filling a jar with water is an example of which of the following process?
a) Batch
b) Semi-batch
c) Neither of them
d) Batch & Semi-batch
Answer: b
Clarification: Since water is entering the jar and does not leave, it is a semi-batch process.
6. Water flowing in plants from tap through a pipe, the process is an example of which of the following process?
a) Batch
b) Semi-batch
c) Neither of them
d) Batch & Semi-batch
Answer: a
Clarification: Since water enters the pipe from one end and leaves from another end, it is a batch process.
7. Water boiling in a container is an example of which of the following?
a) Batch
b) Semi-batch
c) Neither of them
d) Batch & Semi-batch
Answer: c
Clarification: Since nothing is entering in the container but steam is leaving the container, it is neither a batch process nor a semi-batch process.
8. Two reactants enter a vessel and a reaction is carried out, it is an example of which of the following?
a) Batch
b) Semi-batch
c) Neither of them
d) Batch & Semi-batch
Answer: b
Clarification: Since material enters the vessel and operated but does not comes out, so it is a semi-batch process.
9. In a batch process, 70 Kg of H2O and 10 Kg of NaOH and some other reactants enters the vessel, if 100 Kg of the product leaves the vessel, what is the percentage of H2O in the product?
a) 10%
b) 30%
c) 70%
d) 100%
Answer: c
Clarification: Percentage of H2O in the product = (70/100)*100 = 70%.
10. 10 Kg of oil is burnt in a container and taken off from the container if 1% of oil remains on the container wall, how much oil is taken off?
a) 8.9 Kg
b) 9 Kg
c) 9.9 Kg
d) 10 Kg
Answer: c
Clarification: Amount of oil taken off = 10*(1 – 1/100) = 9.9 Kg.
11. In a batch process, 50 Kg of H2O and 40 Kg of CO2 entered a vessel with some H2O, if 100 Kg of product leaves the vessel, what is the percentage of H2O in the product?
a) 10%
b) 30%
c) 60%
d) 80%