Why is the enthalpy of hydration of a chloride ion more negative than that of a bromide ion, using your knowledge of the attractive forces involved.

Chloride ions have a greater charge density than bromide ions due to their smaller size, and therefore attracts the delta positive H in the water molecule more strongly. This would be approximately a 3 mark question, focusing on the knowledge that enthalpy of hydration is different to formation and solution, therefore requiring the inclusion of water, and the knowledge of water's electron density and relative partial charges on the inclusive atoms, to answer the question. Testing the understanding of charge density in ions and molecules and periodic table trends associated.

Further extensions of this question would be to add numerical values and test comfort of use of equations involved, and can also progress into explanations and calculations of enthalpy and entropy, ensuring a firmer grasp of equations and all concerning elements.