Density of CO2 Demonstration & Explanation, Chemwest | Crash Chemistry Academy

But wouldn't that BE the point, to see the bubbles that had been falling due to gravity to start rising due to CO2 evolution in the har? In fact, When the first bubbles hit the CO2 they stay right at the top, even with the lip, because evolving CO2 is pouring over the sides of the container and no longer rising.

Also what is seen here is the bubbles slowly getting lower in the Jar because as the bubbles are being blown toward the opening of the jar from above, which blows out some CO2 and so the bubbles get lower every time.