6.4—The definition of standard enthalpy change of: i reaction, ∆rH ii formation, ∆fH iii combustion, ∆cH iv neutralisation

Know the definition of standard enthalpy change of: i reaction, ∆rH ii formation, ∆fH iii combustion, ∆cH iv neutralisation, ∆neutH v atomisation, ∆atH.

Use —the definition of standard enthalpy change of: i reaction, ∆rh ii formation, ∆fh iii combustion, ∆ch iv neutralisation to connect the rule to the data and decision in the question.

This matters because —the definition of standard enthalpy change of: i reaction, ∆rh ii formation, ∆fh iii combustion, ∆ch iv neutralisation determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the definition of standard enthalpy change of: i reaction, ∆rh ii formation, ∆fh iii combustion, ∆ch iv neutralisation to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The definition of standard enthalpy change of: i reaction, ∆rH ii formation, ∆fH iii combustion, ∆cH iv neutralisation is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.