A plumber entered an open tank as shown on the left at 9.15 am Tuesday morning.. A carbon dioxide gas container was positioned above the tank. A slow leakage of carbon dioxide resulted. The plumber was found dead at 9.30 am that same day.

Look at the video of carbon dioxide and suggest what may have happened?

A sample of the air from inside the tank was taken. Explain the irregular peaks found in the mass spectrum of the air sample below.