Engineering Questions with Answers - Multiple Choice Questions

# Unit Processes MCQ’s – Thermodynamics of Nitration

1 - Question

Is nitration reaction highly exothermic?
a) True
b) False
Explanation: As a huge amount of heat is liberated during nitration reaction therefore it is called exothermic, if heat was to be added it would be called endothermic reaction.

2 - Question

What is the denotion of enthalpy? a) H b) Q c) W d) None of the mentioned
Explanation: the enthalpy of reaction is denoted by H.

3 - Question

The total amount of heat lost by the reacting system from the start of the reaction till the products return to the initial temperature and pressure of the system, what is the heat ‘Q’ called?
a) Heat of Formation
b) Heat of reaction
c) Heat of Nitration
d) All of the mentioned
Explanation: Heat of nitration or heat of reaction or heat of formation ‘Q’ is an exothermic reaction, and it is the total amount of heat given out during nitration reaction.

4 - Question

Calculate the Heat of nitration “Q”: C6H6 + HNO3 ——-> C6H5NO2 + H2O
Qf: -9.7 kgcal +41.5kgcal—–> -2.3kgcal +68.4kgcal
a) +34.3 kgcal
b) -34.3 kgcal
c) +43.3 kgcal
d) -43.3 kgcal

Explanation: Heat of nitration = product – reactant which is +34.3 kgcal.

5 - Question

The heats of nitration decrease with the increase in the number of nitro groups.
a) True
b) False
Explanation: Given by Rinkenbach, the heat of nitration decreases as nitro group increases but heat of formation tends to increase till second and third group and diminishes thereafter.

6 - Question

Which of the following has the highest heat of formation?
a) C6H5-NO2
b) C6H5-CH2-NO2
c) C6H5-NH-NO2
d) C6H5-N(-NO2)2
Explanation: It will have the highest amount of heat of formation because as -NO2 group increase it creates strain in molecules hence less amount of heat required the break the bond.

7 - Question

Which of the following compounds have high heat of formation? (i) b-(2,3,4) trinitrotoluene (ii) a-(2,4,6) trinitrotoluene .
a) (i) b-(2,3,4) trinitrotoluene
b) (ii) a-(2,4,6) trinitrotoluene
c) Both are equal
d) Only (ii) a-(2,4,6) Dinitrotoluene