Final answer:
The reduction in moles in the ideal gas equation does not imply that mass disappears, but instead typically means gas has left the system, as mass cannot be created or destroyed according to mass conservation principles.
Step-by-step explanation:
According to the ideal gas equation PV = nRT, increasing the temperature while keeping pressure (P) and volume (V) constant implies a change in the number of moles (n) of the gas. The question is, if the number of moles decreases, does that mean the mass of the gas simply vanishes? The correct answer is d. Mass conservation principles indicate that the mass of the gas particles cannot vanish, even if the number of moles decreases.
This principle is fundamental to chemistry, stating that matter cannot be created or destroyed in an isolated system. The ideal gas law itself does not account for the disappearance of mass; it simply describes the relationship between gas variables (P, V, n, T). A reduction in moles suggested by the equation would typically imply that gas has exited the system, not that the mass has vanished.