Why is steam hotter than the boiling water?

Every substance requires some energy to change its form. Without energy it can not transform from solid into liquid, from liquid into vapor or from vapor into liquid. Sometimes energy is derived in the form of heat from the atmosphere; otherwise it has to be provided by heating. E.g. one gram water at 0° Celsius freezing point is in the solid form of ice. In order to heat up to boiling point it has to be given 100 calories heat. Cube of an ice already melted into water starts agitating (boiling) at the stage. Now, if one wants to convert that boiling water into steam, heat required for that purpose will be about 540 calories! 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 with another molecule and so on. That is it has property of polarization. It is not property of molecule of water to separate from another and get vaporized. Continuous increase in energy compels it to vaporize as steam, which occupies 1,670 times more space than water. So it has to push away surrounding air molecules in the atmosphere. Some energy is used up in that process. Therefore, it is obvious that steam is inherently hotter then boiling water. In a steam engine water boils at 100° Celsius but the temperature of its steam under pressure is 370° Celsius!


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