# Conceptual thermodynamics/physics question.

Hey Guys,

Say you have an air compressor with a constant volume. And were given the temperature and pressure at the inlet. And also, the temperature and pressure at the outlet. Would the mass of the air at the inlet equal the mass at the outlet? When applying the ideal gas law to the inlet and outlet (assuming air behaves as an ideal gas), is it possible get two different masses? It seems as though that would conflict with the conservation of mass principle.