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repository:phase_changes [2020/09/15 16:51] porcaro1 [Activity] |
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| Below is a graph showing the heating curve for water. Take a look and use the [[https://trinket.io/glowscript/d406d0473c?showInstructions=true | code below]] and then answer the following questions that investigate the relationships between kinetic energy level, temperature, particle movement, etc. | Below is a graph showing the heating curve for water. Take a look and use the [[https://trinket.io/glowscript/d406d0473c?showInstructions=true | code below]] and then answer the following questions that investigate the relationships between kinetic energy level, temperature, particle movement, etc. | ||
| + | |||
| + | {{:repository:water_curve.png?nolink&600|}} | ||
| - If the particle movement is low, the matter is in the %%_____%% state. | - If the particle movement is low, the matter is in the %%_____%% state. | ||
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| ==Post-Coding Questions== | ==Post-Coding Questions== | ||
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| + | {{ :repository:boiling.png?nolink&600|}} | ||
| Now that you understand how the program works to show the relationship between kinetic energy, particle movement, and temperature, it is time to apply your knowledge to improving and extending the power of the program. Develop answers to the following questions by modifying and improving the [[https://trinket.io/glowscript/d406d0473c?showInstructions=true | existing code]]. | Now that you understand how the program works to show the relationship between kinetic energy, particle movement, and temperature, it is time to apply your knowledge to improving and extending the power of the program. Develop answers to the following questions by modifying and improving the [[https://trinket.io/glowscript/d406d0473c?showInstructions=true | existing code]]. | ||
| - Do you think the movement of all particles is the same for all substances given the same energy? For example, should a particle of hydrogen (mass = 1.01 amu) move at the same velocity as a particle of nitrogen (mass = 14.01 amu) for a given temperature? | - Do you think the movement of all particles is the same for all substances given the same energy? For example, should a particle of hydrogen (mass = 1.01 amu) move at the same velocity as a particle of nitrogen (mass = 14.01 amu) for a given temperature? | ||
| - | - What are some of the key equations you would need t model the movement of the particles? | + | - What are some of the key equations you would need to model the movement of the particles? |
| - Which variables are constants and which can change? | - Which variables are constants and which can change? | ||
| - How could we show different movement for different types of substances? | - How could we show different movement for different types of substances? | ||
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| ====Answer Key==== | ====Answer Key==== | ||
| ===Handout=== | ===Handout=== | ||
| + | ==Pre-Coding Questions Part 1== | ||
| + | If the particle movement is low, the matter is in the __**solid**__ state. | ||
| + | - The __**gas**__ state is reached as particles exhibit very high energy at a correspondingly __**high**__ temperature. | ||
| + | - When a gas loses so much energy it turns into a liquid, it undergoes __**condensation**__. | ||
| + | - Since particles in a solid are closely packed together, they can only move __**vibrationally**__ . | ||
| + | - Particles exhibit __**high**__ velocities in the highest energy state. | ||
| + | - Solid particles that absorb so much energy they turn into a gas undergo __**sublimation**__. | ||
| + | - At moderate levels of kinetic energy, the particles can move __**freely**__ and the matter exists as a __**liquid**__. | ||
| + | - Lower energy means __**slower**__ particle movement and __**lower**__ temperature. | ||
| + | - Theoretically, no particle movement occurs at __**-273.15**__ °C (0 K). | ||
| + | - Solids typically have __**lower**__ temperatures than gases. | ||
| + | - If a gas is super heated to thousands of Kelvin, it ionizes and becomes __**plasma**__. | ||
| + | - Increases in __**temperature**__ result in greater particle velocity and therefore greater kinetic energy. | ||
| + | - The Kinetic Theory of Matter says that for hotter temperatures, the __**more**__ of the particles move in matter. | ||
| + | |||
| + | ==Pre-Coding Questions Part 2== | ||
| + | - {{:repository:heating_curve.jpg?nolink&600|}} | ||
| + | - The first plateau is where the matter melts (goes from solid to liquid) or freezes (goes from liquid to solid). Likewise, the second plateau is where the matter boils/vaporizes (goes from liquid to gas) or condenses (goes from gas to liquid) | ||
| + | - See graph and previous answer | ||
| + | - 273.1 K (0 °C) | ||
| + | - 373.1 K (100 °C) | ||
| + | - The graph accurately models the changes between the solid, liquid, and gas phases of water, but does not include the process of ionization | ||
| + | - The first plateau is longer than the second. This indicates that the heat capacity of liquid water is higher than the heat capacity of steam. This means that water is more efficient and carrying heat; it requires more energy to change its temperature in the liquid phase versus the gaseous phase | ||
| + | |||
| + | ==Post-Coding Questions== | ||
| + | - No. We know kinetic energy is equal to $\dfrac{1}{2}mv^2$. Rearranging for velocity, we find $v=\sqrt{\dfrac{2KE}{m}}$. Therefore, for the same energy level, more mass results in less velocity. | ||
| + | - $Q=mc\Delta T$ and $Q=mL$ | ||
| + | - The mass, specific heat capacities, latent heat of fusion, latent heat of vaporization will not change. Energy input is an independent variable and temperature of the substance is a dependent variable. | ||
| + | - We can show different heating curves for different substances by changing the parameters defined in lines 56-62 (specific heat capacities, latent heat of fusion, melting point, etc.) | ||
| + | - Here are some examples:{{:repository:heating_curves.jpg?nolink&600|}} | ||
| + | - If the model occurred at 2 atmospheres of pressure, the melting/freezing point would lower and the boiling/condensing point would increase. We can look at a [[https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Phase_Transitions/Phase_Diagrams#:~:text=Phase%20diagram%20is%20a%20graphical,diagram%2C%20a%20phase%20change%20occurs. | phase diagram]] to see how pressure affects change of state for different substances. One equation that relates pressure, temperature, and volume is the ideal gas law: $PV=nRT$ (note that this only applies to gases) | ||
| ===Code=== | ===Code=== | ||
| [[https://trinket.io/glowscript/2f3f50f661?showInstructions=true | Link]] | [[https://trinket.io/glowscript/2f3f50f661?showInstructions=true | Link]] | ||