7.5—Understand, in terms of intermolecular forces, physical properties shown by substances

Understand, in terms of intermolecular forces, physical properties shown by substances, including: i the trends in boiling temperatures of alkanes with increasing chain length ii the effect of branching in the carbon chain on the boiling temperatures of alkanes iii the relatively low volatility (higher boiling temperatures) of alcohols compared to alkanes with a similar number of electrons iv the trends in boiling temperatures of the hydrogen halides HF to HI.

Use —understand, in terms of intermolecular forces, physical properties shown by substances to connect the rule to the data and decision in the question.

This matters because —understand, in terms of intermolecular forces, physical properties shown by substances determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —understand, in terms of intermolecular forces, physical properties shown by substances to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Understand, in terms of intermolecular forces, physical properties shown by substances is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.