Honors Chemistry 5th
Lab: Triple Point of Dry Ice
When a substance undergoes a triple point change, then it goes through all three of the states of matter: solid, liquid, as well as gas. When all three matters exist at the same time, it is extremely rare and an interesting sight to experience. A triple point is defined, specifically, as “ the temperature and pressure at which the solid, liquid, and vapor phases of a pure substance can coexist in equilibrium” (1). An excellent example of a substance that has the ability to obtain a triple point would be dry ice. Dry ice is solid CO2. Dry ice has many uses, which include keeping items frozen for a long period of time. This is because dry ice is simple to freeze, stays cold, and has a temperature of “-109.3°F or -78.5°C” (2).
Dry ice is very useful for food storage. For example, when shipping meat, dry ice is used at the bottom of the container. This will delay the spoilage of the meat. Dry ice can also remove the tiles from on your floors. This is because the tiles will become looser. They loosen because the chill from the dry ice will shrink the tiles, making it easier to move the tile around. Another use is to brand animals such as horses and cattle. The dry ice super freezes the alcohol; making is easy to brand the animals. Another practical use for dry ice is a more medical approach. Doctors use it to freeze of skin imperfections such as warts. Doctors also use it when shipping biological specimens that are used for testing things in the lab. In addition, it can be used as a chemical retardant. A chemical retardant is “ the extent to which a chemical is held back or delayed” (3). Since the dry ice is so cold, its low temperatures slow and sometimes stop the full chemical reaction that is occurring. Dry ice can also put out fires, because of the CO2 content. It replaces the oxygen in the container. Lastly, it will shrink the dents and dings in peoples’ cars. It condenses the metal and shrinks the bumps.
Each phase change, solids, liquids, and gases, all have different properties. For example, the particles are a solid vibrate intensely while the particles are close together. In a liquid, the particles are farther apart than a solid, and a gas is even farther. A solid has crystals, allotropes, and a definite shape. A liquid has no definite shape, but has a definite volume. In addition, a gas has high expansion on heating, and doesn’t have definite shape or volume. Each atom is part of a different phase change, and each atom make up a bigger load of atoms put together, or molecules.
“Intermolecular forces are seen in various types of molecules. Intermolecular forces are defined as the set of attractive and repulsive forces that occur between the molecules as a result of the polarity of the molecules” (4). A molecule is polar when there is are covalently bonded atoms, and there is a great difference in the electronegativity. There are...