Entropy increases as temperature increases. An increase in temperature means that the particles of the substance have greater kinetic energy. The faster moving particles have more disorder than particles that are moving more slowly at a lower temperature.

The second law states that there exists a useful state variable called entropy. The change in entropy (delta S) is equal to the heat transfer (delta Q) divided by the temperature (T). For a given physical process, the entropy of the system and the environment will remain a constant if the process can be reversed.

Explanation: Second law of thermodynamics tells about the degradation of energy caused due to entropy generation during heat transfer between system & surrounding through a finite temperature difference. The entropy is a property of thermodynamic system which is measure of randomness in a system.

Entropy changes (ΔS) are estimated through relation ΔG=ΔH−TΔS for finite variations at constant T.

A negative change in entropy indicates that the disorder of an isolated system has decreased. For example, the reaction by which liquid water freezes into ice represents an isolated decrease in entropy because liquid particles are more disordered than solid particles.

Entropy is the loss of energy available to do work. Another form of the second law of thermodynamics states that the total entropy of a system either increases or remains constant; it never decreases. Entropy is zero in a reversible process; it increases in an irreversible process.

energy within a system. The entropy of a substance increases with its molecular weight and complexity and with temperature. The entropy also increases as the pressure or concentration becomes smaller. Entropies of gases are much larger than those of condensed phases.

When compressing an ideal gas volume, the entropy increases since the molecules collide more times per second with each other. Similarly, as the molecules have more room to move, the entropy decreases when expanding an ideal gas.

As well, increasing the volume of a substance increases the number of positions where each molecule could be, which increases the number of microstates. Therefore, any change that results in a higher temperature, more molecules, or a larger volume yields an increase in entropy.

Affecting Entropy If you increase temperature, you increase entropy. (1) More energy put into a system excites the molecules and the amount of random activity. (2) As a gas expands in a system, entropy increases. This one is also easy to visualize.

Dissolution of a solute normally increases the entropy by spreading the solute molecules (and the thermal energy they contain) through the larger volume of the solvent.

When salt dissolves in water, sodium and chloride ions are pulled apart to form new weak bonds with water molecules. Pulling them apart takes energy, while forming new bonds with the water molecules releases energy.

When water freezes its entropy decreases. This does not violate the second law of thermodynamics. The second law does not say that entropy can never decrease anywhere. Entropy can decrease somewhere, provided it increases somewhere else by at least as much.

A decrease in the number of moles on the product side means lower entropy. An increase in the number of moles on the product side means higher entropy. If the reaction involves multiple phases, the production of a gas typically increases the entropy much more than any increase in moles of a liquid or solid.

The entropy is decreasing because a gas is becoming a liquid. The entropy is increasing because a gas is being produced and the number of molecules is increasing. The entropy is decreasing because four total reactant molecules are forming two total product molecules. All are gases.

A measure of disorder; the higher the entropy the greater the disorder. In thermodynamics, a parameter representing the state of disorder of a system at the atomic, ionic, or molecular level; the greater the disorder the higher the entropy.

In science, a process that is not reversible is called irreversible. This concept arises frequently in thermodynamics. An irreversible process increases the entropy of the universe. Because entropy is a state function, the change in entropy of the system is the same, whether the process is reversible or irreversible.

When ice melts, the change is endothermic ( H is positive), and entropy increases ( S is positive) as the water molecules lose ordered arrangement of ice crystals.

Entropy is a measure of the disorder or randomness of the system. The greater the randomness in a system, greater is its entropy. The randomness is greater in liquid state as compared to solid state so the entropy increases when ice melts into water.