Gas law

In chemistry, there are several gas laws for easy calculations. Importantly is the gas constant:

$$R=8.31J\cdot K^{-1}{\text{mol}}^{-1}$$

The ideal gas equation, where $p$ is pressure, $V$ is volume, and $T$ is temperature (in Kelvin):

$$pV=nRT$$

The rest assume some variable is constant. Boyle’s law, where temperature is constant:

$$p\propto \frac{1}{V}$$ $$V_1{p}_1=V_2{p}_2$$

Charles’ law, where pressure is constant:

$$\frac{V_1}{T_1}=\frac{V_2}{T_2}$$

Gay-Lussac’s law, where volume is constant:

$$p\propto T$$ $$\frac{p_1}{T_1}=\frac{p_2}{T_2}$$

And the combined gas law:

$$\frac{p_1{V}_1}{T_1}=\frac{p_2{V}_2}{T_2}$$