Sub+Zero+Liquid

=How can I make frozen CO2 release it's energy into a liquid more efficiently?= = = =Introduction/Hypothesis= If I change the liquid then the amount of energy released will vary. = = = = =Background research= Dry Ice is frozen carbon dioxide. It is the gas we exhale. It is also the same gas commonly added to water to make soda water. Dry Ice is -78.5°C. Dry Ice is widely used because it is simple to freeze. Dry Ice changes directly from a solid to a gas -sublimation- in normal atmospheric conditions without going through a wet liquid stage. Therefore it gets the name "dry ice." http://www.dryiceinfo.com/

Dry ice is solidified carbon dioxide. When dry ice melts, it turns into carbon dioxide gas. Carbon dioxide gas is always present in the environment, but in low concentrations. It is colorless and odorless.Carbon dioxide gas is heavier than air, and therefore, it can pool in low areas. http://www.health.ny.gov/environmental/indoors/food_safety/dry_ice.htm

Dry ice is pure, solid carbon dioxide (CO2). As a gas, CO2 exists naturally in our environment. It's called "dry ice" because it does not melt. Dry ice goes directly from a solid to a gas in a process called sublimation.Dry ice keeps items colder for much longer than traditional “wet ice” because dry ice is extremely cold, -78.5°. http://www.continentalcarbonic.com/dryice/

To make dry ice, the liquid carbon dioxide is withdrawn from the tank and allowed to evaporate at a normal pressure in a porous bag. This rapid evaporation consumes so much heat from the surrounding air that part of the liquid carbon dioxide freezes to a temperature of -78° Celsius. The frozen liquid is then compressed by machines into blocks of "dry ice" which will sublimate (return to the gaseous state) when set out at room temperature. http://www.enotes.com/science/q-and-a/how-dry-ice-made-289455

=Materials list= Pot Thermometer Strainer Wire 70% rubbing alcohol Vinegar Water Antiseptic Scale Paper and pen

=Procedure= I will start by weighing the "Dry Ice" to 16 grams. Than I will measure eight cups of the liquid. After this I will start a timer when I put the dry ice in the liquid. I will measure the temp. of the liquid every 5 mins until it hits it's lowest temp. Every 30 mins I will add five grams of dry ice to the liquid. I will record the data while the experiment is In progress Variables and Controls

Independent Variable: The liquid. Dependent Variable:the temp. Of the liquids. Controls: Amount of frozen CO2 and amount of liquid.

=Conclusion= i concluded that rubbing alcohal worked the best for transfering the energy from the frozen Co2