Question

Which of these processes result In an entropy decrease of the system? Check all that apply. - Diluting hydrochloric acid - Boiling water - 2 NO(g) + O₂(g) rightarrow 2 NO₂(g) - Making ice cubes in the freezer

Answer 1

The processes that result in an entropy decrease of the system are the chemical reaction forming NO₂ from NO and O₂ gases, and making ice cubes in the freezer, as these transitions involve increased order or decreased dispersal of molecules.

Step-by-step explanation:

The entropy of a system is a measure of its disorder or randomness. When considering entropy changes in various processes, the following apply:

Diluting hydrochloric acid results in increased entropy, because solute particles become more dispersed in the solvent.

Boiling water results in increased entropy, as the liquid water transitions to gaseous steam where molecules are much more dispersed and disorder increases.

The reaction 2 NO(g) + O₂(g) → 2 NO₂(g) results in decreased entropy. Although all species are gases, the total number of molecules is the same on both sides of the equation, but the formation of a more complex molecule (NO₂) from simpler molecules (NO and O₂) often suggests less randomness or disorder.

Making ice cubes in the freezer, where water goes from a liquid to a solid state, results in decreased entropy since the molecules in the solid state are more ordered.

Therefore, the processes that result in an entropy decrease of the system are the formation of NO₂ gas from NO and O₂ gas and making ice cubes in the freezer.

Answer 2

The processes '2 NO(g) + O₂(g) → 2 NO₂(g)' and 'Making ice cubes in the freezer' result in an entropy decrease of the system.

Step-by-step explanation:

To determine which processes result in an entropy decrease of the system, let's examine each one:

Diluting hydrochloric acid: Entropy increases because there's greater dispersal of matter when the acid is diluted.

Boiling water: Entropy increases because the water transitions from a liquid to a gaseous state, which has higher entropy.

2 NO(g) + O₂(g) → 2 NO₂(g): Entropy decreases because four gas molecules combine to form two gas molecules, resulting in less disorder.

Making ice cubes in the freezer: Entropy decreases because water transitions from a liquid, which has higher entropy, to a solid state, which has lower entropy.

Given these analyses, the processes that result in an entropy decrease are: '2 NO(g) + O₂(g) → 2 NO₂(g)' and 'Making ice cubes in the freezer'.