Suppose you have a pot filled with steam at 100.0 °c and at a pressure of 1.00 atm. The p...

SKETCH

The given situation can be represented with a neat sketch as follows.

Before heating after heating

Here is the initial pressure inside the pot, is the atmospheric pressure and is the weight of the lid and is the final pressure inside the pot after heating.

RESEARCH

If , and are the initial and final temperatures of the pot, then at constant volume, the pressure and temperatures are related by using Gay-Lussac’s law as

…… (1)

SIMPLIFY

The final temperature of the pot such that the lid is removed by the steam is given by

…… (2)

The pressure is defined as the force per unit area, and is given by

Here is the force exerted by the pressure on a lid of area.

Then, the force exerted by the final pressure is given by

…… (3)

The force exerted by the atmospheric pressure is given by

…… (4)

In order to remove the lid, the minimum force can be calculated by equating sum of all the forces in the vertical direction to zero.

That is,

…… (5)

CALCULATE

The initial temperature of the pot,

The initial pressure inside the pot,

The diameter of the pot,

Hence the radius of the pot,

Then, the area of the pot,

Mass of the lid,

The final pressure on the lid is given by

Now substituting all the known values in the equation (2), the final temperature of the pot to remove the lid is given by