Which of the following is most clearly an example of a physical change? a. a solid dissolves when added to a liquid b. a solution color when something is added c. two liquids produce heat when mixed together d. a gas is released when two solutions are combined

Option (A) is the correct answer.

Explanation:

Physical change is defined as a change that does not bring any changes in the chemical properties of a substance.

For example, solubility, density, volume etc are all physical changes.

When sugar dissolves in water then it is a physical change.

Whereas color change may not necessarily shows a physical change because a chemical change can also lead to color change of a solution or substance.

For example, rusting of iron is a chemical reaction in which color change also occurs.

Hence, we can conclude that a solid dissolves when added to a liquid is most clearly an example of a physical change.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.