Additional solute is added to a saturated solution of a solid and a liquid after being heated above room temperature. Once no more of the solute can dissolve, the solution is cooled, and a seed crystal is added. At which of the following points is the solution unsaturated? a. Before the solution is heated, when the concentration of the solute is equal to its solubility in the liquid b. After the solution is heated, but before additional solute is added c. After the solution is heated and more solute is added, but before it is cooled d. Before the solution is heated, when the concentration of the solute is less than its solubility in the liquid

After the solution is heated, but before additional solute is added

Explanation:

An unsaturated solution is a solution that contains less solute than it can normally hold at a given temperature. Hence an unsaturated solution can still dissolve more solute.

When the solution is heated, the saturated cold solution becomes an unsaturated hot solution which is capable of dissolving more solute at this point.

Once more solute is dissolved, the solution becomes saturated again just before it begins to cool since no more solute dissolves in the solution at some point before cooling and addition of seed crystals.

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.

c) should be the answer.