Final answer:
CO gas undergoes compression within a piston-cylinder, following an isothermal process where the PV product remains constant, indicative of Boyle's Law.
Step-by-step explanation:
The scenario described involves a piston-cylinder assembly in which CO gas undergoes compression with a pressure-volume relationship described by PV=constant. The initial conditions given are a pressure P1 of 10 units and a volume V1 of 4 units.
The gas is then compressed to a pressure P2 of 50 units. To appropriately respond to the question, one should understand gas laws -- specifically the isothermal process, wherein temperature remains constant, which is not explicitly stated but is implied by the given pressure-volume relationship.
In the context of an internal combustion engine, after the adiabatic compression phase is the ignition at constant volume, where a spark ignites the mixture, causing a rapid pressure increase without changing the volume.