Showing posts with label temperature. Show all posts
Showing posts with label temperature. Show all posts

What does First Law of Thermodynamics infer us?

  • It is impossible to derive any work without expenditure of an equivalent amount of energy in some other forms. 
  • Heat absorbed by the system should be taken positive. Heat rejected by the system should be taken negative. 
  • For an ideal gas the total kinetic energy (KE) of all its molecules is called internal energy(U). For such a gas the internal energy depends only on Temperature.

Difference between Temperature and Heat

Heat is a form of (Thermal) energy due to the kinetic energy of molecules in a substance. Temperature is measure of hotness or coldness of a body. Temperature is a measurement of the average kinetic energy of the molecules in an object or system.

Mathematically, dQ = k dT; where dQ is the change in heat content, k is a constant of proportionality, and dT is the change in temperature (usually in degrees Kelvin).

Difference between evaporation and vaporization

Vaporization of an element or compound is a phase transition from the liquid phase to gas phase. There are two sorts of vaporization: evaporation and boiling.

Evaporation is a phase transition from the liquid phase to gas phase that occurs at temperatures below the boiling temperature at a given pressure.

Boiling is a phase transition from the liquid phase to gas phase that occurs at or above the temperature the boiling temperature.