12.8—The entropy change in the surroundings, and hence ∆Stotal

Be able to calculate the entropy change in the surroundings, and hence ∆Stotal, using the expression ∆Ssurroundings = −∆H T.

Use —the entropy change in the surroundings, and hence ∆stotal to connect the rule to the data and decision in the question.

This matters because —the entropy change in the surroundings, and hence ∆stotal determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the entropy change in the surroundings, and hence ∆stotal to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The entropy change in the surroundings, and hence ∆Stotal is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.