Second law of thermodynamics | Chemical Processes | MCAT | Khan Academy
khanacademymedicine・2 minutes read
The Second Law of Thermodynamics states that heat never flows from a colder object to a hotter one, ensuring total disorder will never decrease. Entropy, denoted by S, reflects an increase in disorder and plays a crucial role in various physics aspects, emphasizing that in real-world processes, entropy consistently rises in a closed system.
Insights
- The Second Law of Thermodynamics prohibits heat from flowing spontaneously from a cold object to a hot one, ensuring a unidirectional flow from hot to cold due to the statistical favoring of disorder over order.
- Entropy, symbolized by S and governed by the formula S = k * log(W), embodies the increase in disorder within closed systems, as described by Ludwig Boltzmann, intricately tied to the Second Law and impacting the universe's destiny, time's arrow, and various physical phenomena.
Get key ideas from YouTube videos. It’s free
Recent questions
What is the Second Law of Thermodynamics?
The Second Law states heat won't flow from cold to hot.
Related videos
Summary
00:00
Second Law of Thermodynamics: Heat Direction Clarified
- The Second Law of Thermodynamics states that heat will never flow spontaneously from a colder object to a hotter object.
- Heat can be forced from a cold object to a hot object using a heat pump, but it won't happen spontaneously.
- The law ensures that heat will never be seen to flow from a cold object to a hot object in reverse.
- The law is necessary despite conserving energy and other physics laws.
- The law also states that total disorder will never decrease, leading systems from ordered to disordered states.
- The law is based on the statistical likelihood of more disordered states than ordered states.
- The Second Law is a result of counting the possible number of states, favoring disordered states.
- Microstates and macrostates help explain the law, with more microstates for disordered macrostates.
- Heat flowing from hot to cold is a result of energy becoming mixed up and distributed evenly.
- The statistical inevitability of heat flowing from hot to cold is due to the vast number of microstates favoring this direction.
11:45
Entropy: Key to Universe's Disorderly Fate
- Energy naturally dissipates and spreads evenly from hot to cold due to the statistical likelihood of mixing. The scientific term for disorder is entropy, denoted by the letter S, with its formula being S = k * log(W), where W represents the number of microstates for a macrostate. This concept, linked to Ludwig Boltzmann, plays a crucial role in various physics aspects, including the Second Law of Thermodynamics, stating that the total entropy of a closed system always increases, reflecting an increase in disorder.
- Entropy, a mysterious and significant concept, influences the universe's fate, time's direction, and various physics facets. It is intricately linked to the Second Law of Thermodynamics, emphasizing that in real-world processes, the entropy of a closed system consistently rises, signifying an increase in disorder.
