Predict the sign of the entropy change of the system for...

Predict the sign of the entropy change of the system for each of the following reactions: (a) $\mathrm{N}_{2}(g)+3 \mathrm{H}_{2}(g) \longrightarrow 2 \mathrm{NH}_{3}(g)$ (b) $\mathrm{CaCO}_{3}(s) \longrightarrow \mathrm{CaO}(s)+\mathrm{CO}_{2}(g)$ (c) $3 \mathrm{C}_{2} \mathrm{H}_{2}(g) \longrightarrow \mathrm{C}_{6} \mathrm{H}_{6}(g)$ (d) $\mathrm{Al}_{2} \mathrm{O}_{3}(s)+3 \mathrm{H}_{2}(g) \longrightarrow 2 \mathrm{Al}(s)+3 \mathrm{H}_{2} \mathrm{O}(g)$

Predict the sign of the entropy change of the system for each of the following reactions:
(a) $\mathrm{N}_{2}(g)+3 \mathrm{H}_{2}(g) \longrightarrow 2 \mathrm{NH}_{3}(g)$
(b) $\mathrm{CaCO}_{3}(s) \longrightarrow \mathrm{CaO}(s)+\mathrm{CO}_{2}(g)$
(c) $3 \mathrm{C}_{2} \mathrm{H}_{2}(g) \longrightarrow \mathrm{C}_{6} \mathrm{H}_{6}(g)$
(d) $\mathrm{Al}_{2} \mathrm{O}_{3}(s)+3 \mathrm{H}_{2}(g) \longrightarrow 2 \mathrm{Al}(s)+3 \mathrm{H}_{2} \mathrm{O}(g)$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Entropy

Entropy is a thermodynamic property that quantifies the degree of disorder or randomness in a system. It reflects the number of ways a system can be arranged at the microscopic level, with higher entropy corresponding to a greater number of possible microstates.

Entropy Change

The entropy change of a system (?S) during a process indicates whether the system becomes more disordered (positive ?S) or more ordered (negative ?S). This change depends on the reorganization of energy and matter in the reaction.

Phase of Matter and Its Impact on Entropy

The physical state of a substance (solid, liquid, or gas) strongly influences its entropy. Gases, which have molecules that move freely in a three-dimensional space, possess higher entropy compared to liquids and solids. As a result, reactions that form more gas molecules tend to increase the system's entropy.

Stoichiometric Changes and Mole Count

Changes in the number of moles, especially of gaseous species, are crucial in predicting entropy change in a reaction. An increase in the number of gas molecules generally leads to an increase in entropy due to the larger number of available microstates, whereas a decrease in the number of gas molecules typically results in a decrease in entropy.

Transcript

Please give Ace some feedback