THERMO Spoken Here! ~ J. Pohl  ©

TOC     NEXT    ~   1

Ice and Dry Ice: A Competition

Water as a solid (frozen water) is commonly called "ice." On picnics, we put ice into the cooler so it will cool our beer and soft drinks to refreshing temperatures. The ice is cold, as it melts it cools its surroundings.

Carbon dioxide as a solid (frozen carbon dioxide) is called "dry ice." Mail-order steaks, lobster, meatballs and such, frozen at the plant to -40°F are shipped in a styrofoam shipping box with a block of "dry ice" beside them to keep those perishables near -40°F.

These solids are in great need in times of power outage to preserve foods.

Ice is used widely as a substance to provide short-time refrigeration tasks.

The physical properties.

WATER
Initial State: solid saturated at 0°C and 1 atm.	WATER: (Melted) sat. liquid at 0°C and 1 atm.	WATER: (Final State - 2) at 25°C and 1 atm.
T = 0°C vs = 1.09 cm3/g hs = hs*	T = 0°C vf = 1.00 cm3/g hf ≡ hs + hsf      = hs* + 333 J/g	T = 25°C v = 1.00 cm3/g h = hf + cavg( T - 0°C)     = hs* + hsf + cavg(T - 0°C)     = hs* + 333 J/g        + 4.2 J/(g °C)(25 - 0)°C
CARBON DIOXIDE: (Initial State - 1) sat solid at -79°C and 1 atm.	CARBON DIOXIDE: (Sublimed) sat. gas at -79°C and 1 atm	CARBON DIOXIDE: (ideal Gas) at 25°C and 1 atm
T = -79°C vs = 0.64 cm3/g hs = hs*	T = -79 °C vg = 113 cm3/g hg ≡ hs + hsg hg = hs* + 573 J/g	T = 25°C v = 559 cm³/g cp = 0.85 J/g°C cv = 0.66 J/g°C h = hg + cp,avg(T - 0°C)     = hs* + hsf + cavg(T - 0°C)     = hs* + 333 J/g        + 4.2 J/(g °C)(25 - 0)°C

Ice vrs Dry Ice: A Competition

Water as a solid (frozen water) is commonly called "ice." On picnics, we put ice into the cooler so it will cool our beer and soft drinks to refreshing temperatures. The ice is cold, as it melts it cools its surroundings. "Short Term" means for that ice or dry-ice is used to accomplish some cooling task it exhausts itself.

Premise presently unwritted!