Chemical Engineering Questions and Answers – Merging Heat of Formation with Sensible Heat of Compound

This set of Basic Chemical Engineering Interview questions and answers focuses on “Merging Heat of Formation with Sensible Heat of Compound”.

1. How are enthalpies of streams calculated?
a) Relative to the reference state
b) Absolutely
c) Depends on the reaction
d) None of the mentioned

Explanation: Enthalpies of the streams are calculated relative to the reference state.

2. What is the enthalpy of a reaction, if the standard heat of formation of a compound is 10 J and sensible heat of the compound is 5 J?
a) 0
b) 5 J
c) 10 J
d) 15 J

Explanation: Enthalpy of reaction = 10 + 5 = 15 J.

3. What is the enthalpy of a reaction, if the standard heat of formation of a compound is 15 J and sensible heat of the compound is 25 J?
a) 15 J
b) 25 J
c) 40 J
d) 50 J

Explanation: Enthalpy of reaction = 15 + 25 = 40 J.

4. What is the enthalpy of a reaction, if the standard heat of formation of a compound is 15 J, sensible heat of the compound is 25 J, and latent heat of the compound is 10 J?
a) 25 J
b) 40 J
c) 50 J
d) 65 J

Explanation: Enthalpy of reaction = 15 + 25 + 10 = 50 J.

5. What is the enthalpy of a reaction, if the standard heat of formation of a compound is 10 J, sensible heat of the compound is 30 J, and latent heat of the compound is 20 J?
a) 10 J
b) 30 J
c) 40 J
d) 60 J

Explanation: Enthalpy of reaction = 10 + 30 + 20 = 60 J.

6. What is the enthalpy of the reaction from 25oC to 40oC if CP = 10 J/oC, and the reference enthalpy is 10 J?
a) 80 J
b) 120 J
c) 160 J
d) 200 J

Explanation: Enthalpy of reaction = 10 + 254010.dT = 10 + 10*15 = 160 J.

7. What is the enthalpy of the reaction from 10oC to 15oC if CP = 5 J/oC, and the reference enthalpy is 25 J?
a) 25 J
b) 50 J
c) 75 J
d) 100 J

Explanation: Enthalpy of reaction = 25 + 10155.dT = 25 + 5*5 = 50 J.

8. What is the enthalpy of the reaction from 10oC to 25oC if CP = 2 J/oC, and the reference enthalpy is 20 J?
a) 50 J
b) 60 J
c) 75 J
d) 90 J

Explanation: Enthalpy of reaction = 20 + 10252.dT = 20 + 15*2 = 50 J.

9. What is the enthalpy of the reaction from 15oC to 25oC if CP = 3 J/oC, and the reference enthalpy is 15 J?
a) 15 J
b) 30 J
c) 45 J
d) 60 J

Explanation: Enthalpy of reaction = 15 + 15253.dT = 15 + 3*10 = 45 J.

10. What is the enthalpy of the reaction from 50oC to 52oC if CP = 15 J/oC, and the reference enthalpy is 25 J?
a) 10 J
b) 35 J
c) 55 J
d) 65 J

Explanation: Enthalpy of reaction = 25 + 505215.dT = 25 + 2*15 = 55 J.

11. What is the heat transferred to the system if the enthalpy of the output is 10 J and input is 6 J?
a) 4 J
b) 5 J
c) 6 J
d) 8 J

Explanation: Q = ∆Hout – ∆Hin = 10 – 6 = 4 J.

12. What is the heat transferred to the system if the enthalpy of the output is 14 J and input is 8 J?
a) 4 J
b) 6 J
c) 8 J
d) 10 J

Explanation: Q = 14 – 8 = 6 J.

13. What is the heat transferred to the system if the enthalpy of the output is 15 J and input is 10 J?
a) 1 J
b) 2 J
c) 4 J
d) 5 J

Explanation: Q = 15 – 10 = 5 J.

14. What is the heat transferred from the system if the enthalpy of the output is 5 J and input is 10 J?
a) -5 J
b) -10 J
c) -15 J
d) 5 J

Explanation: Heat transferred from the system = 10 – 5 = 5 J.

15. What is the heat transferred from the system if the enthalpy of the output is 25 J and input is 10 J?
a) 5 J
b) -5 J
c) 15 J
d) -15 J

Explanation: Heat transferred from the system = 10 – 25 = -15 J.

Sanfoundry Global Education & Learning Series – Basic Chemical Engineering.

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