Well, thanks for the replies, folks, but the chemical nature of bleach isn’t what I was looking for, exactly (as noted, it’s easy to look that up).
What I was looking for was how they make bleach - do they bubble gas through a big tank of some chemical? Mix various powders and liquids? Apply heat? What?
If, hypothetically, I had a pile of money with which to build a bleach factory what equipment and facilities would I need? How long does it take to make a batch? How to control the concentration?
Also - I’m still interested in the history - what was the first commercial sodium hypochlorite factory, did it use a didn’t method than modern, and what did people do before it was made commercially? Is sodium hypochlorite something a pioneer family could cook up in the back yard like soap, or did they use some other alternative instead?