# Chemical Process Calculation Questions and Answers – Species Mole Balances-I

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This set of Chemical Process Calculation Multiple Choice Questions & Answers (MCQs) focuses on “Species Mole Balances-I”.

1-5. For a given reaction
C2H6 + Cl2 → C2H5Cl + HCl
Assume that the percentage conversion of the limiting reactant is 60% and the feed composition in mole percent is 50% C2H6, 40% Cl2 and 10% N2.
1. What is the mole percent of C2H6 in the product?
a) 24
b) 26
c) 40
d) 60

Explanation: Take basis = 100 moles, Reacting moles in the reaction = 0.60*40 = 24 moles, moles left = 50 – 24 = 26.

2. What is the mole percent of Cl2 in the product?
a) 16
b) 24
c) 26
d) 40

Explanation: Moles left = 40-24 = 16.

3. What is the mole percent of C2H5Cl in the product?
a) 16
b) 24
c) 26
d) 40

Explanation: Moles of C2H5Cl produced in the reaction = 24 moles.

4. What is the mole percent of HCl in the product?
a) 16
b) 24
c) 26
d) 40

Explanation: Moles of HCl produced in the reaction = 24 moles.

5. What is the mole percent of N2 in the product?
a) 10
b) 16
c) 24
d) 40

Explanation: N2 is not involved in the reaction, Moles of N2 = 10 moles.

6-10. In a bioreactor, these following reaction can occur to perform the fermentation process-
C6H12O6 → 2C2H5OH + 2CO2
C6H12O6 → 2C2H3CO2H + 2H2O
The tank is initially charged with 6000 kg of 15% solution of glucose in water. After fermentation, 160 kg of CO2 produced and 100 kg of unreacted glucose left in the broth.

6. How much water is there in the tank after fermentation?
a) 94.45 kg
b) 5100 kg
c) 5194.45 kg
d) None of the mentioned

Explanation: Species mole balance for each.

7. How many moles of C6H12O6 reacted in the first reaction?
a) 1.414
b) 1.818
c) 2.424
d) 4.848

Explanation: Species mole balance for each.

8. How much Ethanol is there in the product in kgs?
a) 67.43
b) 167.43
c) 267.43
d) 367.43

Explanation: Species mole balance for each.

9. How much propenoic acid is there in the product in kgs?
a) 178
b) 278
c) 378
d) 478

Explanation: Species mole balance.

10. How many kgs of C6H12O6 is used in second reaction?
a) 127.54
b) 227.54
c) 327.54
d) 427.54