atmospheric heating

The specific heat of a substance is the amount of heat required to increase the temperature of a unit mass of it through a unit temperature. Its units in cgs system are cal g -1 o C -1 . In mks system, it is measured in kilocal kg - 1 o C - 1 . The SI unit is J kg - 1 K - 1 . Th..

Standard Enthalpy of Reaction - As the heat of a reaction varies with temperature it is desirable to fix up a standard or a reference state. A substance is said to be in standard state when it is present in its most stable state at 298 K under a pressure of one atmosphere. The h..

Green house gases in the atmosphere behave much like the glass panes in a green house. Green houses are like small glass houses whose transparent glass roof and walls allow sunrays to pass through. It keeps the heat from escaping, thus allowing vegetables and flowers to grow ev..

When we heat a solid, we add energy to the system increasing the vibration of the particles. Eventually these particles break free from their binding forces and fuse. Fusion is the change of state from solid to liquid. This is generally referred to as melting. The temperature at which th..

Breaking down large molecules by heating at high temperature and pressure is termed as thermal cracking. Thermal cracking is further classified into the following classes. Liquid phase thermal cracking process: The higher boiling fractions e.g., fuel oil, lubricating oil are converted ..

Boiling - Vapour pressure measures the tendency for the molecules to escape from liquid to the gas phase. At lower temperatures the vapour pressure of a liquid is much lower than the pressure on the surface of the liquid. When the temperature of the liquid is gradually increased, its vapour pressur..

When steel (containing 1% of aluminium) is heated in an atmosphere of ammonia at 550 o C - 600 o C, the surface of steel becomes very hard. This is called nitriding . Nitrogen formed by the dissociation of ammonia reacts with iron and aluminium to form the respective nitrides on..

Helium (from the Greek helios, for sun) was detected by Janssen and Lockyer independently in the spectrum of the sun in the year 1868. At that time, it was thought that helium is present only in the atmosphere of the sun. Later on, in 1885, helium was found by Ramsay on the earth by ..

Enthalpy - The change in internal energy gives the heat change accompanying a chemical reaction at constant volume. However, most of the chemical reactions carried out in laboratories, are open to normal atmospheric conditions. A chemical reaction in a laboratory may incur chang..

The change in internal energy gives the heat change accompanying a chemical reaction at constant volume. However, most of the chemical reactions carried out in laboratories, are open to normal atmospheric conditions. A chemical reaction in a laboratory may incur change in ..