6.2—That, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy

Know that, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy change.

Use —that, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy to connect the rule to the data and decision in the question.

This matters because —that, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —that, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —That, by convention, exothermic reactions have a negative enthalpy change and endothermic reactions have a positive enthalpy is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.