A measure of the degree of disorderliness in a chemical system is known as the

Step 1: Analyze the question The question asks for the term that measures the degree of disorderliness (randomness) in a chemical system.

Step 2: Explain the concept Let's look at each option:

• Activation energy: the minimum energy reactants need to start a reaction.
• Enthalpy (H): the heat content of a system. Its change, ΔH, is the heat absorbed or released at constant pressure.
• Entropy (S): the measure of disorder or randomness in a system. The more disordered the particles, the higher the entropy.
• Equilibrium: the state in which the forward and backward reaction rates are equal.
• Free energy (G): the energy available to do useful work. It combines enthalpy and entropy: ΔG = ΔH − TΔS.

Step 3: Apply the concept Disorderliness is exactly what entropy describes. For example:

• Solid → liquid → gas: entropy increases, because the particles become more free and random.
• Dissolving salt in water: entropy increases.
• A reaction that produces more gas molecules than it uses: entropy increases.

So the term we want is entropy.

Step 4: Answer The correct option is C. entropy.

Tip: Link Entropy with Extent of Erraticness (randomness), or remember "Entropy = Energy spread out, Everything messy." Whenever you see "disorder" or "randomness" in a chemistry question, think entropy (S).