Here’s another video that might come in useful when teaching about acids and alkalis - Rosie Coates shows us her favourite chemistry demonstration involving a giant test-tube and some universal indicator solution. As well as showing us a fantastic demo, Rosie explains how the science of acids and alkalis can have important real-world applications.
This is another video where it’s really worth hitting the “HQ” button on the youtube player after you’ve hit “play”.
...the follow up to this would be to add CaOH3 which is what is being considered to de-acidifiy the oceans AND draw (sequest) CO2 from the atmosphere - problem & solution (maybe).