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Fall 2020 CHEM 1A Properties of Gases CHEM 1A Properties of Gases & Kinetic Molecular Theory Begin Here: Start Virtual ChemLab, at the top of the screen select the Gases Laboratory. Go to the stockroom and click on the Clipboard. On the Clipboard select Balloon experiment Ideal. The displays on the left hand side represent the values for P, T, T, and n. You are able to change the Pressure, Temperature, and the moles of gas. You can change the values on the display by moving the lever on the display up or down. You can also change the value on the display by typing a value. Part I: Gas Laws Relation between Pressure (P) and Volume (V) a. Use the balloon experiment already setup in the laboratory to describe the relationship between pressure (P) and volume (V). Click on the Save button next to the green exit arrow. Increase the Pressure from 1.000 atm to 10.000 atm in increments of 1 atm using the lever on the Pressure display. Click Stop to stop recording data, and a data link icon will appear in the lab book. To help keep track of your data links, enter ‘Ideal Gas Run 1’ next to the link. b. Select the lab book and click on the data link icon for Ideal Gas Run 1. In the Data Viewer window, select all the data by clicking on the Copy Data button and copy the data using CTRL-C for Windows or CMD-C for Apple. Paste the data into Google Sheets and create a Scatter plot with Volume on the x-axis and Pressure on the y-axis. c. Be sure to enter your Pressure-Volume data in the table below. Pressure (atm) Volume (L) Pressure (atm) Volume (L) 1 6 2 7 3 8 4 9 5 10 P, V Scatter Plot What can you conclude about the effect of pressure on volume? Write a mathematical relationship using the proportionality symbol (∝). Relation between Temperature (T) and Volume (V) a. Set the V, P, T, and n as follows: V = 3.062 L P = 1.000 atm T = 100.00 oC n = 0.100 b. Use the balloon experiment already setup in the laboratory to describe the relationship between pressure (V) and volume (T). Click on the Save button next to the green exit arrow. Increase the Temperature from 100.00 oC to 1000.0 oC in increments of 100 oC using the lever on the Temperature display. Click Stop to stop recording data, and a data link icon will appear in the lab book. To help keep track of your data links, enter ‘Ideal Gas Run 2’ next to the link. c. Select the lab book and click on the data link icon for Ideal Gas Run 2. In the Data Viewer window, select all the data by clicking on the Copy Data button and copy the data using CTRL-C for Windows or CMD-C for Apple. Paste the data into your Google Sheets file and create a Scatter plot with Volume on the x-axis and Temperature on the y-axis. d. Be sure to enter your Temperature-Volume data in the table below. Temperature (K) Volume (L) Temperature (K) Volume (L) 1 6 2 7 3 8 4 9 5 10 T, V Scatter Plot What can you conclude about the effect of temperature on volume? Write a mathematical relationship using the proportionality symbol (∝). __________________________________________________________________________ Relation between n (moles of gas) and Volume a. Set the V, P, T, and n as follows: V = 2.447 L P = 1.000 atm T = 298.15 K n = 0.10 b. Use the balloon experiment already setup in the laboratory to describe the relationship between Volume (V) and the moles of gas (n). Click on the Save button next to the green exit arrow. Increase the value of n from 0.100 to 0.190 in increments of 0.01 using the lever on number of moles display. Click Stop to stop recording data, and a data link icon will appear in the lab book. To help keep track of your data links, enter ‘Ideal Gas Run 3’ next to the link. c. Select the lab book and click on the data link icon for Ideal Gas Run 3. In the Data Viewer window, select all the data by clicking on the Copy Data button and copy the data using CTRL-C for Windows or CMD-C for Apple. Paste the data into your Google Sheets file and create a Scatter plot with Volume on the x-axis and moles on the y-axis. d. Be sure to enter your moles of gas-Volume data in the table below. n (moles) Volume (L) n (moles) Volume (L) 1 6 2 7 3 8 4 9 5 10 n, V Scatter Plot What can you conclude about the effect of moles on volume? Write a mathematical relationship using the proportionality symbol (∝). ________________________________________________________________________________________________ Part II: Based on the data collected and your Scatter Plots, complete the table below. Relationship Direct or Indirect Whose Law ? Parameters Constant P vs V T vs V n vs V Part III: Use Kinetic Molecular Theory to explain each of the relationships in the table above. For full credit use complete sentences in your explanations. (a) P vs V (b) T vs V (c) n vs V Part IV: Derivation of Ideal gas Equation a. Since volume is inversely proportional to pressure and directly proportional to temperature and moles, we can combine these three relationships into a single proportionality by showing how V is proportional to 1/P, T, and n. Write one combined proportion to show the relationship of volume to pressure, temperature and moles. b. The above proportional relationship can be converted into a mathematical equation by inserting a proportionality constant (R) into the numerator on the right side. Write this mathematical equation and rearrange with P on the left side with V. c. The equation above is known as the Ideal Gas Law. Using data for volume, temperature, pressure and moles from one of the gas experiments, calculate the value for R with units of L atm K-1mol-1. (Show all work and round to three significant digits.) d. Using the conversion between atmospheres and mmHg (1 atm = 760 mm Hg), calculate the value for R with units of L mmHg K-1mol-1. (Show all work and round to three significant digits.)