This set of Chemical Process Calculation Multiple Choice Questions & Answers (MCQs) focuses on “Limiting and Excess Reactant-I”.
1. Which is the excess reactant in the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O, if the initial moles of C5H12 and O2 are 2 and 8, respectively?
a) C5H12
b) O2
c) CO2
d) H2O
View Answer
Explanation: C5H12 is the excess reactant since it has more moles compared to the stoichiometric ratio with O2.
2. Which is the limiting reactant in the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O, if the initial moles of C5H12 and O2 are 2 and 8, respectively?
a) C5H12
b) O2
c) CO2
d) H2O
View Answer
Explanation: O2 is the limiting reactant because the stoichiometric ratio requires 8 moles of O2 for 1 mole of C5H12, and there is not enough O2 to completely react with the C5H12.
3. In the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O, if 2 moles of C5H12 and 8 moles of O2 are initially present, how many moles of C5H12 remain unreacted after completion?
a) 0
b) 1
c) 2
d) 3
View Answer
Explanation: Moles left = Initial mole – extent of the reaction*stoichiometric coefficient.
4. For the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O, given an initial feed of 2 moles of C5H12 and 8 moles of O2, how many moles of O2 are left after the reaction completes?
a) 0
b) 2
c) 4
d) 6
View Answer
Explanation: O2 is the limiting reactant, so it will be completely consumed in the reaction.
5. How many moles of CO2 are produced in the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O?
a) 5
b) 6
c) 7
d) 8
View Answer
Explanation: The reaction produces 5 moles of CO2 for every 1 mole of C5H12 reacted.
6. How many moles of H2O are produced in the reaction: C5H12 + 8 O2 → 5 CO2 + 6 H2O?
a) 5
b) 6
c) 7
d) 8
View Answer
Explanation: The reaction produces 6 moles of H2O for every 1 mole of C5H12 reacted.
7. What is the extent of the reaction for C5H12 + 8 O2 → 5 CO2 + 6 H2O, if 2 moles of C5H12 and 8 moles of O2 are used?
a) 0
b) 1
c) 2
d) 3
View Answer
Explanation: The extent of the reaction is determined by the amount of the limiting reactant consumed, which in this case is O2.
8. For the reaction CO2 + 4 H → CH2O + H2O, if the initial moles of CO2 and H are 4 and 10 respectively, what is the number of moles of CO2 left after the reaction is complete?
a) 0
b) 1
c) 1.5
d) 2.5
View Answer
Explanation: The stoichiometric ratio between CO2 and H is 1:4, so after 2.5 moles of H are consumed, 1.5 moles of CO2 will remain.
9. What is the extent of the reaction for CO2 + 4 H → CH2O + H2O, given that 4 moles of CO2 and 10 moles of H are used?
a) 0
b) 1
c) 1.5
d) 2.5
View Answer
Explanation: The extent of the reaction is determined by the amount of the limiting reactant, which in this case is H. The reaction proceeds with an extent of 2.5.
10. How many grams of CO2 are produced in the reaction CO2 + 4 H → CH2O + H2O, if the extent of the reaction is 2.5?
a) 0
b) 1
c) 1.5
d) 2.5
View Answer
Explanation: Moles of CO2 produced = 2.5 = Extent of the reaction.
Sanfoundry Global Education & Learning Series – Chemical Process Calculation.
To practice all areas of Chemical Process Calculation, here is complete set of 1000+ Multiple Choice Questions and Answers.
