Every substance requires some energy to change its form. Without energy, it cannot transform from solid to liquid, from liquid to vapor or from vapor to liquid. Sometimes, energy is derived in the form of heat from the atmosphere; at other times, the energy has to be provided by heating.
For example, one gram of water at 0° Celsius (freezing point) is in the solid form of ice. In order to heat up to a boiling point, it has to be heated to 100° Celsius. An ice cube that’s already melted starts agitating (boiling) at that stage. Now, if one wants to convert that boiling water into steam, the heat required for that purpose will be about 540° Celsius! Here, a question immediately arises: How did the figure of calories rise so high?
There is a reason for such a high increase. Every molecule of water tries to remain attached to another molecule and so on. This is called the property of polarization. It is not the property of molecules of water to separate from one another and get vaporized. Continuous increase in energy compels it to vaporize as steam, which occupies 1,670 times more space than water.
Hence, the heat has to push away the surrounding air molecules in the atmosphere. Some energy is used up in that process. Therefore, it is obvious that steam is inherently hotter than boiling water. In a steam engine, water boils at 100° Celsius; however, the temperature of its steam under pressure is 370° Celsius!
These fascinating facts about water are something that we can potentially observe in a simple science experiment or video.
- Why does heat make paper curl up?
- Which liquid substance boils when it is cold?
- Why does water gurgle when it’s flowing out from a bottle?
- How does gargling with salt water help to cure sore throat?
- Why sugar dissolves faster in hot water than in cold water?
- Why hot water appears milky white when drawn from the faucet?