Reversibility and Equilibrium Practicals: Evidence You Can Trust | Year 12 Chemistry

Full lesson, notes and practice questions: https://hscscience.com.au/subjects/ch... How do you show in the lab that a reaction is reversible, and that an equilibrium really responds to a change? Push it, then bring it back: heat pink cobalt chloride crystals until they turn blue, add water and watch the pink return, and compare burning magnesium, which never comes back. Then plan the iron thiocyanate disturbance investigation with an untouched reference tube, one change per tube and a dilution control, and heat and cool the cobalt solution in a stoppered tube. Ends with validity, reliability, accuracy and the risk assessment. 0:00 The practical question 0:26 Evidence for reversal 1:31 Keep the system contained 1:56 Set up a reference 3:23 Check for dilution 3:54 Heat and cool cobalt 4:57 Risk assessment 5:58 Practice questions 8:11 Key notes Chemistry 2017: Year 12 Module 5, Equilibrium and Acid Reactions. Supports the reversibility and Le Chatelier’s principle practical investigations. Syllabus dotpoints (NSW Chemistry Stage 6, 2017, Module 5): "conduct practical investigations to analyse the reversibility of chemical reactions, for example: cobalt(II) chloride hydrated and dehydrated iron(III) nitrate and potassium thiocyanate burning magnesium burning steel wool (ACSCH090)" "investigate the effects of temperature, concentration, volume and/or pressure on a system at equilibrium and explain how Le Chatelier’s principle can be used to predict such effects, for example: heating cobalt(II) chloride hydrate interaction between nitrogen dioxide and dinitrogen tetroxide iron(III) thiocyanate and varying concentration of ions (ACSCH095)" Official 2017 course: https://www.nsw.gov.au/education-and-... Prerequisite: Changing temperature, concentration and pressure (Le Chatelier's principle). Next: Writing and interpreting equilibrium expressions. #Year12Chemistry #Equilibrium #HSCScience