Surface Chemistry: Factors affecting the adsorption Nature and surface area of the adsorbent: Activation of adsorbent is necessary to provide vacant sites on its surface for the adsorbate to bind. The solid crystals need to be broken down to form small particles or powdery form to increase in surface area for binding. Most of the … Read more
Surface Chemistry: Adsorption Chemisorption Chemical adsorption or chemisorption results from a chemical interaction between the adsorbate and adsorbent. Therefore, formed a bond (covalent, ionic, metallic) with bond energy more than 10 kcal/mol is much stronger than that for physical adsorption. The heat liberated during chemisorption is in the range of 50-500 kJ/mol. The enthalpy of … Read more
Surface Chemistry: Adsorption Physisorption Surface Science is the study of physical and chemical phenomena that occur at the interface of two phases such as solid-liquid interfaces. Adsorption is a surface phenomenon in comparison to absorption, which is a bulk phenomenon. A molecule present in the interior of solid (or liquid) is pulled by other molecules … Read more
Chemical Kinetics: Arrhenius Equation The Arrhenius equation is generally used to show the effect of a change of temperature on the rate constant and therefore on the rate of the reaction. If the rate constant doubles, for example, so will the rate of the reaction. An increase in temperature creates an increase in the KE … Read more
A solid solution is defined as a mixture of 2 solids of crystalline nature which together exist in the form of a crystal lattice or new crystalline solid. The mixture can be made efficient by combining 2 solids when in liquids, they are melted at a higher temperature and afterward, by the cooling effect, … Read more
There’s dissolution of gases in liquids, but in general, to a little extent only. When the gases dissolve in liquid, gas molecules’ ability to freely move all over solvent’s volume is highly restricted. So, if solvent’s volume is very small, as frequently the case is, efficiently, the gas is being compressed. Due to these two … Read more
Semiconductors Semiconductors have a small energy gap between the valence band and the conduction band. Electrons can make the jump up to the conduction band, but not with the same ease as they do in conductors. Semiconductors consist of small gap in between conduction band and valence band. The conduction electrons can jump over the … Read more
Insulators: The band gap energy or the forbidden energy gap is very high in between conduction band and valence band. This is the reason why there’s no conductivity present in such substances. In insulating material case, there is a big forbidden gap between valence band and conduction band. It is practically impossible for the electron … Read more
Semiconductors: There’s a short band gap present in between conduction band the valence band. Therefore, when the trigger or incitation process is done, then electron’s small fraction with sufficient energy jumps. Nevertheless, the conductivity of these substances can be increased by accelerating the doping or the temperature. Below is the table of conduction band, energy … Read more
The conductor is usually a substance in which there is a property of passing various types of energy. Following is the explanation of band theory and electrical conductivity in conductors. Metallic bonding: (Fermi gas) or Free valence electrons and fixed ions Conductivity is dependent additionally on temperature, the difference. If the temperature increases, the movements … Read more