In deriving the ideal-gas equation from the kinetic- molecular model, we ignored potential energy due to the earth’s gravity. Is this omission justified? Why or why not?
Solution 18DQ The ideal gas equation is derived from the assumption that, the interaction of the gas particles in between themselves is zero. With that, the gravitational effects are extremely less. We know that, gravity is the weakest force in nature. The universal gravitational constant value is extremely small and the masse of the gas particles is also very less. So, the gravitational effect and interaction are omitted from the ideal gas equation. By including the gravitational interaction also, the equation will be invariant up to many degrees of accuracy. CONCLUSION: And the most important fact is, the ideal gas is an abstract concept and there is no such gas which does not interact with each other. By it’s definition itself, it does not interact with the gravitational field. So, it’s appropriate to ignore the effect while deriving the equation.