eli5: why does soap get more “soapy” in hot water and disappear in cold water?

163 views

eli5: why does soap get more “soapy” in hot water and disappear in cold water?

In: 25

Hot things have more energy. More energy means things tend to want to move more. The soap particles will disperse faster in the water because of this and when the soap is spread out, it’s “soapy water”.

It happens in cold water too, it’s just that the soap is a bit more clumpy and not as evenly spread.

By soapiness I assume you mean bubbles and foam. Warm air rises to the surface of the water and collides with the soap, which it cant pass through, forming bubbles. Foam is just tiny bubbles. Cold water has much less warm air trying to escape and as such produces much less.

Soap is half fat, half water-soluble stuff. The fat part will congeal like wax in colder temps. Maybe not into one lump but in many small lumps you can’t see. In hotter water, the molecules are moving around more so the fat parts don’t have as much of a chance to stick together, so the soap molecules are getting out there and doing their thing more.