Why does hot water take dirt off dishes so much easier than cold water?
In: Chemistry
Hot water has a lower surface tension then cold water, therefore it gets through pores of substances (usually oil) more easily. It’s like adding surfactants (e.g. washing up liquid) to a dish to clean. Surfactants lower the surface tension and makes it easier to wash off dirt.
Heat is just measure of motion. Something being “hot” just means it has molecular mobility. Now just think of it this way, something moving faster has a better chance of dislodging something stuck than something moving slower. And that’s all it is, the water is imparting it’s heats, or it’s motion, into the stuck on dirt.
The steam (water vapor) in a dishwasher seems to do a much better job than the temperature of water (based on my extensive hand-washing experience). As long as that water temperature between “HOT” and “COLD” is really the hot from the hot water heater, and cold is room temperature.
Latest Answers