Thermal Equilibrium
When there is no transfer of heat between two bodies in contact, the the bodies are called in thermal equilibrium.
Zeroth Law of Thermodynamics
If two bodies A and B are separately in thermal equilibrium with thirtli body C, then bodies A and B will be in thermal equilibrium with each other.
Triple Point of Water
The values of pressure and temperature at which water coexists inequilibrium in all three states of matter, i. e., ice, water and vapour called triple point of water.
Triple point of water is 273 K temperature and 0.46 cm of mere pressure. Specific Heat
The amount of heat required to raise the temperature of unit mass the substance through 1 ° C is called its specific heat.
It is denoted by c or s.
Its SI unit is joule / kilogram- ° C '( J / kg- ° C). Its dimensions is [ L 2 T-2 θ-1 ].
The specific heat of water is 4200 J kg-1 ° C-1 or 1 cal g-1 C-1, which high compared with most other substances.
Gases have two types of specific heat 1. The specific heat capacity at constant volume( Cv). 2. The specific heat capacity at constant pressure( Cr).
Specific heat at constant pressure( Cp) is greater than specific heat constant volume( CV), i. e., Cp > CV.
For molar specific heats Cp – CV = R where R = gas constant and this relation is called Mayer’ s formula.
The ratio of two principal sepecific heats of a gas is represented by γ.