Hi all Tomorrow I plan to show my students this demo (rsc instructions). Up until now I've mainly taught science up to IGCSE only so have less experience setting up practicals for key stage 5. I'm a teacher and technician! Just wondered if anyone had any safety tips or other advice for this practical. My conc HCl is at 32% and I'm not used to using conc HCl in front of students, what would be the best method of transferring it to measuring cylinder etc? Also understand CoCl2 should be handled in a fume cupboard (switched off) until in solution - this isn't a chemical I've worked with before. Once equilibrium set up (violet colour) we'll be adding HCl and H2O to observe colour Changes and also altering the temperature using water baths to observe the shift in equilibrium position. Thanks for any advice.