Chemical Thermodynamics Question 481
Question: Which of the following is an example of endothermic reaction [MP PMT 1980]
Options:
A) $ C_2H_2+2H_2\to C_2H_6;\Delta E=-314.0,kJ $
B) $ C+O_2\to CO_2;\Delta E=-393.5,kJ $
C) $ N_2+O_2\to 2NO;\Delta H=+180.5,kJ $
D) $ 2H_2+O_2\to 2H_2O;\Delta H=-571.8,kJ $
Show Answer
Answer:
Correct Answer: C
Solution:
Heats of combustion are always exothermic except for the oxidation of N as, $ N_2+\frac{1}{2}O_2\to N_2O $
$ \Delta H=+,ve $
$ N_2+O_2,\to 2NO $
$ \Delta H=+,ve $