Changes in Pressure & State

Master pressure & state changes! Explore matter, dry ice, and phase transitions.

1. Match the vocabulary word to its definition. Freezing A liquid becoming a solid. Melting A solid becoming a liquid. Sublimation A solid becoming a gas; skipping the liquid sate. Evaporation A liquid becoming a gas. Matter Anything that has mass and takes up space. Density The amount of matter in a specified place. 2. Match the image to the state of matter. Solid Gas Liquid 3. Consider the container below. How could you change the pressure to turn the matter inside into a solid? Increase the pressure. Decrease the pressure. 4. Consider the container below. How could you change the pressure to turn the matter inside into a liquid? Increase the pressure. Decrease the pressure. 5. Consider the container below. How could you change the pressure to turn the matter inside into a liquid? Increase the pressure. Decrease the pressure. 6. Consider the container below. How could you change the pressure to turn the matter inside into a gas? Increase the pressure. Decrease the pressure. Use the text below to answer the following questions. Phase Changes of Carbon DioxideSolid carbon dioxide (CO2) is commonly known as dry ice. Carbon dioxide freezes at a temperature of -78.5°C, which makes dry ice very good at keeping things cold. Liquid carbon dioxide does not exist at atmospheric pressure. Because of this, dry ice immediately changes to a gaseous state when it is warmed. This can be seen as a benefit of using dry ice, since no liquid is left in the container that is being used to keep things cold. A shipping company wants to determine how effectively dry ice can keep food frozen in a cooler system over time. 7. What is dry ice made of? Oxygen Carbon Dioxide Nitrogen Carbon Monoxide 8. At what temperature does CO2 freeze? -178.5o C -17.85o C -78.5o C -7.85o C 9. Does liquid CO2 exist at atmospheric pressure? No Yes 10. Why do shipping companies use dry ice to transport food? Dry ice is really good at keeping things cold. Dry ice is readily available. Dry ice doesn't leave any liquid in the container. Both A and C. Use the graph below to answer the following questions. The scientist uses an infrared thermometer to measure the temperature of the air inside of a cooler with dry ice over a period of 48 hours. The data collected is shown in the graph above. 11. What was the initial temperature in the cooler? 20 oF 20 oC -20 oC -60 oC 12. What was the lowest temperature of the cooler? -42 oC -65 oC -79 oC -100 oC 13. How long did it take for the cooler to reach its coolest temperature? 12 hours 24 hours 36 hours 48 hours 14. Which statement correctly describes how the energy of the carbon dioxide molecules in the dry ice changes during the first 12 hours of the experiment? (There are 2 correct answers.) The average thermal energy of carbon dioxide decreases throughout the experiment. The average thermal energy of the air in the cooler increases throughout the experiment. The average kinetic energy of the carbon dioxide molecules increases as it becomes a gas. As dry ice changes from a solid to a gas, it absorbs thermal energy from the surrounding air. As the average number of molecules in the cooler decreased, the thermal energy also decreased. 15. Liquid carbon dioxide only forms at pressures above 5.1 atm. If the cooler system could be safely sealed, how would increasing the pressure of the system create liquid carbon dioxide? Increasing the pressure of solid carbon dioxide would cause the carbon dioxide molecules to move farther apart, forming a liquid. Increasing the pressure of solid carbon dioxide would cause the carbon dioxide molecules to move closer together, forming a liquid. Increasing the pressure of gaseous carbon dioxide would cause the carbon dioxide molecules to move farther apart, forming a liquid. Increasing the pressure of gaseous carbon dioxide would cause the carbon dioxide molecules to move closer together, forming a liquid.