Chemical Process Calculation Questions and Answers Part-17

1. A membrane is used for separation of gases from waste. If the feed stream contains 20% CO2 and 80% SO2 and the product contains 25% CO2 and 75% SO2. Assume that the waste stream amounts to 80% of the input stream. What is the composition of CO2 in waste stream?
a) 0.1875
b) 1.1685
c) 0.1485
d) 0.1285

Answer: a
Explanation: Mole balances for both the gases

2. A membrane is used for separation of gases from waste. If the feed stream contains 20% CO2 and 80% SO2 and the product contains 25% CO2 and 75% SO2. Assume that the waste stream amounts to 80% of the input stream. What is the composition of SO2 in waste stream?
a) 0.8175
b) 0.8165
c) 0.8145
d) 0.8125

Answer: d
Explanation: Mole balances for both the gases.

3. Below given statements for distillation is
In distillation, a liquid mixture is boiled to produce a vapour of different composition that moves away from the liquid.
a) True
b) False
c) Partially correct
d) None of the mentioned

Answer: d
Explanation: In distillation, a liquid mixture is boiled to produce a vapour of different composition that moves away from the liquid.

4. In a distillation column for a feed of1000 kg the output is 80% of the feed and remaining 20% is waste. The feed contains 20% of Acetone and rest Water. The product contains 20% of Acetone and 40% of Water. How much Acetone is there in waste?
a) 20 kg
b) 40 kg
c) 60 kg
d) 80 kg

Answer: b
Explanation: Mass balance for each component

5. In a distillation column for a feed of1000 kg the output is 80% of the feed and remaining 20% is waste. The feed contains 20% of Acetone and rest Water. The product contains 20% of Acetone and 40% of Water. Moles of water in waste?
a) 4.45
b) 8.89
c) 16.67
d) 20.48

Answer: b
Explanation: Mass balance for each component.

6. Correct statement for a tie component in material balance is
a) Enters a process in only one stream
b) Leaves in only one stream
c) Does not react inside the process
d) All of the mentioned

Answer: d
Explanation: A tie component full-fills a, b, c all three conditions.

7. For the given drying process, a material (Called SRU) is dried and feed and outputs are as shown in the figure.
167
A, in kg is
a) 1666.67
b) 2666.67
c) 3666.67
d) 4666.67

Answer: b
Explanation: Mass balance for each component.

8. For the given drying process, a material (Called SRU) is dried and feed and outputs are as shown in the figure.
167
B, in kg is
a) 666.67
b) 566.67
c) 466.67
d) 366.67

Answer: a
Explanation: Mass balance for each component.

9. A batch of 20% of Acetic acid is prepared by mixing the Acetic acid of two containers A and B. A (400 kg) contains 80% of Acetic acidand B contains 15% of Acetic acid. How much kg of acid is prepared?
a) 5700
b) 7600
c) 8000
d) 9800

Answer: b
Explanation: Mass balance for each component

10. A batch of 20% of Acetic acid is prepared by mixing the Acetic acid of two containers A and B. A (400 kg) contains 80% of Acetic acidand B contains 15% of Acetic acid. How much B in kg is used?
a) 4000
b) 6000
c) 8000
d) 10000

Answer: c
Explanation: Mass balance for each component.