Co2 is a real gas or not?

There are no ideal gases. They don't exist. It's a model designed to predict the behavior of gases based on several assumptions. Real gases differ from ideal gases such that,. Real gases have small attractive and repulsive forces between particles and ideal gases do not. read more

So no, carbon dioxide is not an ideal gas because it has attractive and repulsive forces between particles, gas particles have a volume, and the collisions are not elastic. Generally speaking, a real gas approaches ideal behavior in high temperatures and low pressures. read more

Technically CO2 is not an ideal gas, because collisions aren't always perfectly elastic, there is some interaction (Van der Walls) between molecules etc. Then again this is true of all gasses. The ideal gas equations can still be used on CO2 as a (very) good approximation. read more