Thermodynamics and Chemical Kinetics

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.

Biliquid propellants use two separate liquid components (fuel and oxidizer) stored in different tanks and mixed at combustion. Alcohol (fuel) and N₂O₄ (oxidizer) fit this. Nitroglycerine and nitrocellulose form double-base solid propellants, not biliquid.

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.

An isothermal process is one where temperature remains constant throughout. In thermodynamics, different prefixes indicate different constant conditions: iso-same, thermal-temperature (isothermal), baric-pressure (isobaric), choric-volume (isochoric). Adiabatic means no heat exchange, not constant temperature.

The rate of a chemical reaction does not depend on pressure.

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to proceed. They provide an alternative reaction pathway with a lower energy barrier, allowing reactions to occur faster under physiological conditions. Enzymes do not change the free energy difference between reactants and products, do not primarily work by releasing heat, and do not just increase molecular motion.

All are correct statements.