Chemistry question:

[NealIRC]

Originally Posted by NealIRC

1.

The freeze-thaw cycle of water. When temp goes below freezing, water becomes ice, and it's density goes down. Therefore, it's volume goes up, causing the pipes to crack. This also explains why potholes form in the winter.

My question is - how strong does the pipe or ground have to be, to withstand the force on the expansion of ice from water.

Apparently stronger than steel, as steel pipes break.
Apparently stronger than concrete, as potholes form.

I wonder about if you put water in a tungsten can and then freeze it?

Looking for the compressibility of ice and has it been thoroughly compared with the cracking pressure of various kinds of pipe or materials?

Here's something I got from a physics PhD.


There's a lot of work on expansion force strength. From what i've seen, 25000 psi - 110000psi depending on the state of water.
I think regular pipe in your home can withstand 3000psi. Not even close.
There are plenty of ways to keep ice from breaking container.. and you would end up with a slightly different phase of ice.

[NealIRC]

Which chemicals out there are good for killing bacteria and viruses? I can only think of 4, with 2 of them being alcohols.

1. Bleach (5.25%, 8.25%, and 10%).
2. Hydrogen peroxide (3%).
3. Ethyl alcohol (70%).
4. Isopropyl alcohol (70%, 91%).

What else?

There's also strong acids and bases. HCl, H2SO4, but I don't know where to find/buy strong bases. Drano is essentially the same as bleach.

[Chemistry_Guy]

As a graduate student I used azide salts to keep bacteria from growing in my buffer solutions, mostly sodium azide. It is pretty nasty stuff, though, so I wouldn't recommend keeping it around the house.

Vinegar is surprisingly good as a disinfectant, considering how harmless it is to humans. I use cheap whiskey to kill bacteria when I clean my pipes (tobacco, not plumbing), as I would hate to accidentally ingest rubbing alcohol or denatured ethanol.

There are countless substances that can be used as disinfectants, the challenge is finding things that kill the bugs but are safe to store and use around the house and don't damage the things you are cleaning. It also helps if they are readily available and inexpensive. For example, aqua regia will kill just about anything, but if you try sterilizing metal surfaces with it you will dissolve away the metal.

[NealIRC]

Originally Posted by NealIRC

Which reaction is more dangerous: when 2 hot gases combine to form a cold gas, or 2 cold gases combine to form a hot gas.

1 is spontaneous only and the other is non-spontaneous only.

Originally Posted by NealIRC

Home insulation question.

Fiberglass, polyurethane foam, vermiculite. Any you recommend, as well as outside that list? Which is the most toxic 1 that they put in attics, that look like pink cotton candy or white.

And, if there something you can install to your windows in the winter time, assuming glass isn't good for insulation? I presume being next to the window in the winter time is the coldest part.

Thanks.

What really puzzles me... is why is the home insulation used in the winter (absorb cold) the same for use in the summer?

What's something that can absorb heat?

If it's the same thing, then what does insulation even do at warm temperature (absorb warm?).