pH Probe: Can anyone suggest a pH probe with data logging function/capabilities for use with our senior science groups?

pH Probe: Can anyone suggest a pH probe with data logging function/capabilities for use with our senior science groups?
Laboratory doors security: Is it a requirement that science room doors be locked when n
Licence to purchase chemicals: Hi - I've had a few Year 11 students (Occ Health & Safety topic) ask about licences for chemicals held in schools, specifically the Science Dept.
Disposal of reactants of chemical clock ac
Making Polyurethane foam: Could someone please tell me where I can find instructions for a Year 11 chemistry prac for making polyurethane foam?
Mercury Thermometers: how do we dispose of mercury thermometers?
Making ionic compounds: I need help to understand the products we ended up with when we ran this practical.
Enzyme preparation for experiments: Could you provide guidance in the correct preparation of enzymes such as trypsin, pepsin and amylase for enzyme digestion practical activities?
Mercury II Thiocyanate: Hi all. Does anyone know if we can use this in high schools? it is used to make Pharoah's serpent?
Disposal of potassium permanganate: I would like to know how to dispose of potassium permanganate 0.02M solution. The MSDS states it is not a hazard but that it must not be put down the drain.