Combined Gas Comparison - Heat & Thermodynamics Step by Step

When pressure, volume, and temperature all change, the ideal-gas ratio pV over T stays constant.

highlighted = computed this step

Compute the first gas ratio

The first state uses pressure 2, volume 6, and temperature 300 kelvin.

\frac{p_iV_i}{T_i} = \frac{2\ \text{Pa}\cdot 6\ \text{m}^{3}}{300\ \text{K}}

The second state uses pressure 4, volume 4, and temperature 400 kelvin.

\frac{p_fV_f}{T_f} = \frac{4\ \text{Pa}\cdot 4\ \text{m}^{3}}{400\ \text{K}}

Both states give one twenty fifth joule per kelvin.

\frac{pV}{T} = \tfrac{1}{25}\ \text{J/K}