Carbon Dioxide Curiousities chemistry

* It won't burn.
* No matter how cold you make it, you can't turn it into a liquid at atmospheric pressures.
* It sublimes, going directly from a solid (dry ice) to a gas (one way to make very creepy fog).
* It's heavy. Burning 1 gallon of gasoline (weighing about 8 pounds) produced 25 pounds of CO2.
* You can make a supercritical fluid out of it - a state of matter that is neither solid, liquid, nor gas.
* It's a critical ingredient in chocolate chip cookies - produced in situ by the reaction of sodium bicarbonate and the potassium salt of tartaric acid.