Read the given passage and answers following questions :
In 1916 Langmuir proposed theory of adsorption of a gas on the surface of the solid to be made up of elementary sites each of which would adsorb one gas. It is assumed that all adsorption sites are equivalent and the ability of a gas molecule to get bound to any one site is independent whether or not the neighbouring sites are occupied. Additionally, it is also assumed that dynamic equilibrium exists between adsorbed and non adsorbed gas molecule.
Following principles can be obtained from Langmuir adsorption isotherm
• The gas adsorbed behaves ideally in a vapour phase.
• Only monolayer adsorption takes place.
•The surface of the solid is homogeneous.
• There are no lateral interactive force between the adsorbate molecule.
• The adsorbed gas molecules are localized.
Who proposed the theory of adsorption of a gas on the surface of the solid ?