Chemical Thermodynamics Question 306
Question: If the heat of formation of $ CO_2 $ is $ -393,kJ $ . The amount of heat evolved in the formation of 0.156 kg of $ CO_2 $ is [MH CET 2004]
Options:
A) $ -1357.9kJ $
B) $ -1275.9,kJ $
C) $ -1572.0,kJ $
D) $ -1165.5,kJ $
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Answer:
Correct Answer: C
Solution:
Heat of formation of a substance is the heat exchanged when one mole of that substance is formed by its constituent elements. $ \because $ Heat evolved when 1 mole $ (44g),CO_2 $ is formed $ =393,kJ $
$ \therefore $ Heat evolved when $ 0.156,Kg,(156g) $ is formed $ =\frac{393\times 156}{44} $
$ \therefore $ $ \Delta H $ for the process $ =1572,kJ $
$ =-1572.0,kJ $