Answer to Question #321356 in General Chemistry for TJW

Question

C2H2 (g) + 2 H2 (g) → C2H6 (g) + 42 kcal

a. Is this reaction exothermic or endothermic? Briefly explain your choice.

b. Would you expect entropy to increase or decrease for this reaction? Briefly explain.

Answer 1

a. A type of chemical reaction that releases heat energy during the process.

In this reaction, the energy is part of the equation on the products side. It is given out this tell us that the reaction is exothermic.

b. Entropy measures disorder. The more things that you have (that don’t interact) the more disorder you have and the higher the entropy. In the reaction you presented there are 3 molecules of reactants and only 1 of product. Fewer “things” represent less disorder than many “things” so less entropy.