Chapter 18.5, Problem 53LC

Interpretation Introduction

Interpretation: The enthalpy for the decomposition of nitroglycerine reaction is -1427 kJ/mol, using this information the information about its enthalpy and entropy is to be stated.

Concept Introduction: A reaction is spontaneous when the entropy is offset by a large release of heat. Also, a reaction is spontaneous if an increase in enthalpy is offset by an increase in entropy.

Answer to Problem 53LC

Both the enthalpy and entropy for the decomposition of nitro glycerine increase.

Explanation of Solution

The given chemical equation is;

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}\left(l\right)\to {\text{6N}}_{\text{2}}\left(g\right)+{\text{O}}_{\text{2}}\left(g\right)+12{\text{CO}}_{\text{2}}\left(g\right)+10{\text{H}}_{\text{2}}\text{O}\left(g\right)$

From the above reaction, it is clear that the entropy of the reaction increases due to an increase in the randomness via the formation of gaseous molecules on the product side. Thus, enthalpy also increases due to an increase in entropy.

Also, due to the release of a tremendous amount of energy the reaction is highly explosive.