Thermodynamic Terms
Chapter Name : Thermodynamics |
Sub Topic Code : 102_11_06_01_05 |
Topic Name : Thermodynamic Terms |
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Sub Topic Name : The Internal Energy as a State Function - Heat |
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Introduction
• This exchange of energy, which is a result of temperature difference is called heat, q. • The q is positive, when heat is transferred from the surroundings to the system. • q is negative when heat is transferred from system to the surroundings.
Pre-Requisites:
System, heat
Activity:
Heating water by immersion rod.
Real Life Question:
How do you tell whether one surface is hot or not?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Heat | Change in energy due to temperature difference. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Pot of cold water, glass of hot water, thermometer | Put the glass of hot water inside the pot of cold water. See how the water temperature changes in both |
Real life uses :
Explaining heat
changes occurring in various systems
Places to visit :
Bathroom.
Practical examples around us
| Examples | Explainations |
|---|---|
| Change in internal energy | This can be brought by simply heating water in bucket by and immersion rod, or by doing mechanical work, like churning the water. |
What you learn in Theory:
• Internal energy, U, of the system is a state function. • The positive sign expresses that wad is positive when work is done on the system. • wad will be negative, if the work is done by the system.
What you learn in Practice:
Enthalpy doesn’t depend on the path.