Amout of energy needed to warm air

[troymcfont]

Hi,

How do I calculate the amount of energy needed to warm air from 20 °C to 100 °C in a constant volume (1680 cm³)?

Thank you.

 

[phyzguy]

The specific heat of dry air is about 1.0 kJ/kg-K, and the density of dry air is .0013 g/cm^3, so the air in 1680 cm^3 will weigh 2.2 g or 2.2E-3 kg. So to heat it up 80 C will take:

E = 1.0 kJ/kg-K * 2.2E-3 kg * 80 K = 0.18 kJ = 180J.

Here's a good source for some of these constants.

 

[troymcfont]

Thank you!