Entropy lesson - Senior High School Chemistry - oustanding

This is a lesson on entropy for Senior High School Chemistry that has been thoroughly planned and resourced. The lesson starts by getting students to classify reactions as endothermic or exothermic. This is required knowledge so please read through these before the lesson and make sure that students have covered this content. This starter activity could be printed and laminated to be used as a card sort. The concept of entropy is introduced along with the first and second laws of thermodynamics. A stack of Jenga bricks or a stack of cards could be used to illustrate that disorder is a more likely arrangement (gases) than order (solid). The custard powder combustion demo is used to illustrate that entropy changes in the system help predict whether a reaction is spontaneous (whether it happens). Details of how to carry this out can be found online at the UK Royal Society of Chemistry wiki and other websites. Students then are introduced to the three formulae needed and complete a worksheet that I have created where they calculate entropy of a system, entropy of the surroundings and total entropy. This is used to predict whether the reactions happen (i.e. whether there is a positive value). Note that balanced equations have not been provided and students at this level should be capable of writing these and sharing them with the class. Markschemes are provided for the entropy calculations. The lesson ends with a comparison of the importance of entropy and enthalpy. Please rate this resource and leave feedback.