Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. 2 KClO3(s) → 2 KCl(s) + 3 O2(g) c. Na(s) + 2 Cl2(g) → NaCl(s) d. N2(g) + 3 H2(g) → 2 NH3(g)
Ch.18 - Free Energy and Thermodynamics
Chapter 18, Problem 27
Which of these processes is spontaneous? a. the combustion of natural gas b. the extraction of iron metal from iron ore c. a hot drink cooling to room temperature d. drawing heat energy from the ocean's surface to power a ship
Verified Solution
Video duration:
1mThis video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Spontaneity in Chemical Processes
A spontaneous process is one that occurs naturally without the need for external energy input. It is driven by the increase in entropy, or disorder, of the system and its surroundings. Spontaneity is often assessed using Gibbs free energy, where a negative change indicates a spontaneous reaction at constant temperature and pressure.
Recommended video:
Guided course
04:20
Spontaneity of Processes
Entropy
Entropy is a measure of the disorder or randomness in a system. In thermodynamics, processes that increase the total entropy of the universe are favored and tend to be spontaneous. For example, when a hot drink cools, the energy disperses into the surroundings, increasing entropy.
Recommended video:
Guided course
02:46
Entropy in Thermodynamics
Gibbs Free Energy
Gibbs free energy (G) is a thermodynamic potential that helps predict the spontaneity of a process at constant temperature and pressure. The change in Gibbs free energy (ΔG) is calculated as ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy. A negative ΔG indicates a spontaneous process.
Recommended video:
Guided course
01:51
Gibbs Free Energy of Reactions
Related Practice
Textbook Question
3407
views
Open Question
A reaction has ΔH°rxn = -112 kJ and ΔS°rxn = 354 J/K. At what temperature is the change in entropy for the reaction equal to the change in entropy for the surroundings?
Open Question
What is the molar entropy of a pure crystal at 0 K, and what is the significance of the answer?
Textbook Question
Which of these processes are nonspontaneous? Are the nonspontaneous processes impossible? a. a bike going up a hill b. a meteor falling to Earth c. obtaining hydrogen gas from liquid water d. a ball rolling down a hill
1299
views
Textbook Question
Two systems, each composed of two particles represented by circles, have 20 J of total energy. Which system, A or B, has the greater entropy? Why?
418
views
Textbook Question
Two systems, each composed of three particles represented by circles, have 30 J of total energy. How many energetically equivalent ways can you distribute the particles in each system? Which system has greater entropy?
1463
views