Question

If water is made from hydrogen and oxygen molecules then how can dry ice be made of carbon dioxide? What actually is dry ice?

Answer 1

Regular ice is made from freezing water. Water freezes at zero degrees Celsius, or +32 degrees Fahrenheit.

Solid carbon dioxide formed by cooling and by giving pressure on carbon dioxide gas which does not melt so it is known as dry ice.
"Dry ice" is made from frozen carbon dioxide gas. Carbon dioxide is an odd substance because at regular pressure, it is only found in gas and solid forms: the stuff in the air you breathe and dry ice. So when dry ice "melts" it goes directly into the gas form!At really high pressures, carbon dioxide does form a liquid phase. Anyway, dry ice is much, much colder because carbon dioxide freezes at a lower temperature:-79 degrees Celsius or -109 degrees Fahrenheit!