# Rate of pressure increase of contained air being heated

• hjb39

#### hjb39

Wondering if I have a sealed steel tank filled with air and the air temp is 0C and the air pressure in the tank is 0, then heat is applied to the tank - what will the pressure be 100C? At 200C? At 300C? I assume the rate of expansion is constant, but correct me if this is wrong. Thanks.

Are you familiar with the ideal gas law: ##PV=nRT##. It states (among other things) that the pressure is directly proportional to the temperature.

A brief note about the quantities: ##P## is the absolute pressure. So what you call 0 pressure is actually 1 atmosphere pressure or about 100 kPa. Also, the T is thermodynamic temperature measured in Kelvin. So 0 C is 273 K.

I assume the rate of expansion is constant
Careful. There is no "expansion" if the tank is rigid. It's the P part of @Dale 's formula that counts. V would be constant.
I suggest you google "Gas Laws" and search around for a link that makes sense to you. There will be a range of difficulty in the hits you get.
But Air is pretty well behaved at the temperatures you quote and you can treat it as a 'ideal gas' as long as you make sure there's very little water vapour.

Dale