Thermodynamics and Chemical Kinetics

Due to strong chemical bonds formed between adsorbent and adsorbate, the heat of adsorption is generally high.

A small quantity of the catalyst is generally sufficient to catalyse a reaction.  (i) For example, in the decomposition of hydrogen peroxide, one gram of colloidal platinum can catalyse 108 litres of hydrogen peroxide.

Enzymes catalyze reactions by lowering the activation energy required to reach the transition state. This means the transition state in a catalyzed reaction is energetically more favorable (lower in energy) compared to an uncatalyzed reaction. However, the transition state still has higher energy than both the substrate and product.

An exergonic reaction is a chemical reaction where the change in the Gibbs free energy is negative, indicating a spontaneous reaction.

The standard enthalpy of reaction is the enthalpy change that occurs in a system when one mole of matter is transformed by a chemical reaction under standard conditions.

Homogeneous catalysts function in the same phase as the reactants, but the mechanistic principles invoked in heterogeneous catalysis are generally applicable. Typically homogeneous catalysts are dissolved in a solvent with the substrates. One example of homogeneous catalysis involves the influence of H+ on the esterification of esters, e.g. ,methyl acetate from acetic acid and methanol.

The cage effect in chemistry describes how properties of a molecule are affected by its surroundings. In a solvent a molecule is often more accurately described existing in a cage of solvent molecules, the so-called solvent cage. Reactions occur when a molecule occasionally jumps out and meets another molecule. Typical cage lifetime in a solvent cage is 10⁻¹¹ s .

The function of the catalyst is to alter the speed of the reaction rather than to start it.

Helmholtz free energy is a thermodynamic potential which measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume. For such a system, the negative of the difference in the Helmholtz energy is equal to the maximum amount of work extractable from a thermodynamic process in which temperature and volume are held constant.

This option is correct as with the help of catatyst the rate of reaction increase because it lowers the energy barriers for the reaction.

An entropic force acting in a system is a phenomenological force resulting from the entire system's statistical tendency to increase its entropy, rather than from a particular underlying microscopic force.

Changes in which physical properties like shape, size and state change without formation of new substance are called physical changes.

A reversible change is a change that can be undone or reversed, so a piece of iron is heated to red hot and tis softens it. It is then beaten into the desired shape. It is a reversible change.

In which the molecule present in the food undergoes change to form molecule.

Adsorption is a surface phenomenon where molecules adhere to the surface of solids or liquids. Absorption involves bulk penetration throughout the material. Catalysis is a process of increasing reaction rate, and induction refers to electromagnetic phenomena.