Total Entropy Calculations If we take the reaction between sodium and chorine, we know that this is a very exothermic reaction and also involves a decrease in entropy as a solid is produced ...
Introducing Entropy You may have wondered why it is that endothermic reactions occur at all, after all, what can be the driving force behind endothermic reactions if the products end up in a...
Solution & Hydration Definitions Enthalpy of solution The standard enthalpy change of solution (ΔHsolꝋ) is the enthalpy change when 1 mole of an ionic substance dissolves in sufficient w...
Polarisation of Ions Theoretical lattice energies assume a perfect ionic model where the ions are 100% spherical and the attractions are purely electrostatic So overall, there has a been a c...
Born-Haber Cycles A Born-Haber cycle is a specific application of Hess’ Law for ionic compounds and enable us to calculate lattice enthalpy which cannot be found by experiment The basic prin...
Lattice Energy Lattice energy As with bond enthalpy, lattice energy (ΔHlattꝋ) can be expressed as a formation or dissociation process As a formation process, it is the enthalpy change when 1...
Weak Acid - Strong Base Titration In this example, strong sodium hydroxide, NaOH (aq), is being added to weak ethanoic acid, CH3COOH (aq) NaOH (aq) + CH3COOH (aq) → CH3COONa (aq) + H2O (l) T...
Action of a Buffer Solution A buffer solution is a solution which resists changes in pH when small amounts of acids or alkalis are added A buffer solution is used to keep the pH almost const...
在关注夏季成绩的同时，也不能忘了秋季考试和报名关键时间点，尤其是准备秋季参加考试的同学，CIE十月大考将近，一起来看看报考重要时间节点和Alevel、IGCSE各科考试时间吧。 报考的关键时间节点 2022年报名截止...
