Why does hot water clean more effectively than cold water?

Question

PLUS: Apart from bacteria issues why don't we use hot water to clean our teeth.

Answer 1

I have no idea maybe the heat breaks up the dirt molecules?

Answer 2

that is a very good question but i dont know

very hot water, like boiling, kills bacteria, but the heat of the water we use to wash up or have a shower or wash the floor isnt hot enough for that i would have thought??

Answer 3

the molecules in hot water are vibrating more than in cold water,this is why it is hot in the first place.

this will agitate other particles more.

Answer 4

Originally we had to boil water by heating it on the range/fire and it was hard work.  Why not use cold when you are not going to be able to use it really hot anyway.

In modern times most people have boilers which boil on demand but before that we used hot water tanks which didn't always keep the water hot enough to kill the REALLY nasty bacteria.  Water could sometimes sit around in these tanks at the wrong kind of temperatures bacteria thrieve on for days and reach really dangerous levels.

This is one of the reasons you should always use cold water for the kettle.  The bacteria will eventually become tiny invisible spores which are nolonger destroyed when boiled.

Answer 5

Hot water breaks down oils and fats whereas cold water solidifies them.

Think about what happens when you pour hot water (as opposed to cold) into an oily pan - that's why it's more effective. Works the same way when washing clothes.

Don't know about you, but I don't brush my teeth with water - I brush them with toothpaste!

Answer 6

That is the way it is.

The physical properties of water changes with temperature.

It looses the property of keeping gases in it, and gets better keeping solid materials in it. Try to make cold water take up sugar. Then raise the temperature and try again. The change is big.

But why?

I cant tell.

Answer 7

Because it lessens and loosens up the stickiness and can melt away spots.

I use hot water to clean up those sticker stains.

But I use cold to get rid of gum off of carpets.

They're both useful actually.