Energy must transfer to the carbon dioxide from its surroundings
solid carbon dioxide (CO2) is stored under high pressure. Solid CO2 gets converted directly to gaseous state on decrease of pressure to 1 atmosphere without coming into liquid state. This is the reason that solid carbon dioxide is also known as dry ice
It reacts with oxygen to produce carbon dioxide, water, and heat.
Air contains oxygen, carbon dioxide, nitrogen, and other compounds. We take carbon dioxide into our lungs all the time, but our lungs keep the oxygen. However, if you were in a room with ONLY carbon dioxide, you would die--not from carbon dioxide per se, but from lack of oxygen.
In the alveoli which is in the lungs
Sublimation is not a reaction, but a physical change (change of state or phase). The solid turns instantly to gas, rather than first going to liquid state. At the right temperature and pressure, this can happen. A common example of this is dry ice (solid carbon dioxide) turns to carbon dioxide gas without first going through the liquid phase. This occurs, because liquid carbon dioxide cannot exist at 1 atmosphere pressure. Sublimation can happen with solid water (ice) as well, at the right temperature. Ice cubes in a freezer can seemingly disappear over time.
it disappears
carbon dioxide is produced.
When you smoke, ride a vehicle, or use electricity, you let out carbon dioxide.
There is carbon dioxide in the atmosphere. You have been breathing it in all your life.
Carbon dioxide is released from water at high temperature.
Nothing, carbon dioxide and oxygen do NOT react.
you die
solid carbon dioxide (CO2) is stored under high pressure. Solid CO2 gets converted directly to gaseous state on decrease of pressure to 1 atmosphere without coming into liquid state. This is the reason that solid carbon dioxide is also known as dry ice
Most likely you'll get an explosion that creates carbon dioxide and water. But that will only happen if you get the mixture hot enough or the pressure is high enough.
At normal atmospheric pressure, carbon dioxide goes directly from the solid phase to the gas phase without ever being a liquid in between. The technical term for this is "sublimation." It is possible to have liquid carbon dioxide at higher pressures, so strictly speaking it's not true to say that solid carbon dioxide can never melt ... it just doesn't happen at normal pressures.
you will die
nothing will happen at all