Boiling water - amount of steam

wasia

Hello!

There is an observation I have made when boiling water - amount of steam getting out of the kettle increases when the heating is turned off. Could anyone help to explain that?

The experiment goes like this. Take a kettle, start heating the water. The amount of the steam getting out increases (the kettle has a small hole at the top of it). When the water approaches the boiling point, the steam is getting out of the kettle at an impressive rate. However, if the heating is turned off (before or after boiling - does not matter) the amount of steam increases even further.

I wonder if
a) I am unable to judge the amount of steam accurately.
b) The form of the kettle (tested on 2) is relevant.
c) There is a good thermodynamical explanation.

Thanks.

Mapes

This is a common observation. What we're calling "steam" here is condensed water droplets (technically, steam is invisible water vapor). When you turn off the heat, the water vapor leaving the water surface condenses sooner, and the amount of "steam" therefore increases.