Question

ReviewI Constants Periodic Table The air that surrounds us is mostly empty space, and it can be almost a factor of one thousand less dense than water. Within that mostly empty space, gas molecules are moving around at high speed and colliding with each other, and if you are in an enclosed space, they are also colliding with the walls. We can more easily observe the behavior of a gas by confining it to a container with a known volume, and then we can change or measure its volume, exerted pressure, temperature, and number of moles. These are considered the macroscopic properties of gases because we can observe them when many gas particles are present (as opposed to a single atom or molecule). For example, when a balloon is filled with air, you can see the size (volume) of the balloon increase and feel the increasing pressure inside of it by squeezing it with your hands These macroscopic properties can be experimentally measured with relative ease: A thermometer measures temperature, a manometer measures pressure, and a ruler can be used to estimate the dimensions to determine volume (if the container lacks graduated markings). The number of moles can theoretically be determined in a manner similar to that used for solids and liquids, but since the density of gas is extremely small, the direct determination of the number of moles can be elusive owing to very small mass values. Instead, let us explore the relationship between these macroscopic properties to determine whether the behavior of gases allows us to more easily determine the number of moles of gas and, furthermore, whether it is possible to predict the behavior of the gas when one of its macroscopic properties is changed. The Simulation described below allows you to conduct virtual tests on either a pure gas or a gas mixture. Click on the image below to explore this simulation, which allows you to change the conditions of ideal gases (pressure, volume, temperature, and number effects on the behavior of gas particles. When you click the simu lation link, you will be able moles) and observe the select among Overview, Learning Outcomes, and Experiment tabs Chemistry Simulations:Knetic Molecular Theory of Gasses Devin Leang Outcomes The maincomaanents of the view in the Riston glass containes . Controls to change ther espariment ps unbir df molisore change varisble by moirg ther diding the slder bar d Fate Het The Overview and Learning Outcomes tabs generally describe what can be achieved with the Simulation and what you will learn after working with it. Under the Experiment tab, click on the button titled Run Demonstration to explore the macroscopic and microscropic properties of gases through a guided tutorial (in that order). Click on the button labeled Run Experiment to explore the macroscopic and microscopic behavior gases on your own. Part A For each exercise, you can simulate the described conditions by changing the values in the Run Experiment tool of the Simulation. To be able to measure the effects on pressure or volume, slide the Rspd bar in the Properties box to either P (atm) or V (L), respectively. The slider bar for either pressure or volume will turn yellow when it is selected, and it becomes the only dependent variable, i.e., the value you measure in response to changing the other properties. Note that, when either pressure or volume is selected with Rspd, the respective value can no longer be directly controlled. Let us first examine the behavior of an ideal gas when we force the volume to be a value of our choosing. We can examine how changes to the absolute temperature and number of moles affect the pressure of the gas particles (by selecting pressure with Rspd such that pressure cannot be controlled). e of 275.00 K occupy Assume that 0.02 mol of at a tempera and the OSSure values whon the tomperature or Dumber ofme lume of 2.30 L. Use the Run Experiment tool in the Simulation to determine the initial pressure of the gas is changed to complete the folloud iatoments. Match the words in the left column to the appropriate blanks the sentences on the right. Make certain each sentence is complete before submitting your answer. View Available Hint(s) View Available Hint(s) Help Reset 0.76 atm The initial pressure of the argon gas is 0.21 atm From the initial conditions (0.02 mol and 275.00K), if you increased the amount of argon to 0.06 0.69 atm mol, the new pressure would be Therefore, pressure with the 0.20 atm number f moles in proportion. direct From the initial conditions (0.02 mol and 275.00K), if you increased the temperature by 80.00 K, inverse Therefore, pressure the new pressure would be with proportion decreases temperature in increases 0.25 atm 0.18 atm 0.59 atm Submit Part B For this exercise, you can simulate the described conditions by changing the values in the Run Experiment tool of the Simulation. To be able to measure the effects on the gas volume, slide the Rspd bar in the Properties box volume is selected with Rspd, its value can no longer be directly controlled. V (L) so that the volume bar is highlighted (turns yellow). In this way, volume becomes the only dependent variable. Note that, when Suppose a piston automatically adjusts to maintain a gas at a constant pressure of 11.80 atm. For the initial conditions, consider 0.05 mol of helium at a temperature of 255.00 K This gas occupies a volume of 0.09 L under those conditions. What volume will the gas occupy if the number of moles is increased to 0.08 mol (n2) from the initial conditions? What ch new yolu Occupy if the temperature is increased to 355.00 K (T2) from the initial conditions? Remember to reset the experiment to the initial conditions before determining Express the volumes in liters to two decimal places separated by a comma. View Available Hint(s) VA D tn2, volume at T2 0.144,0.125 L volume Previous Answers Submit Incorrect; Try Again; One attempt remaining

Answer 1

aing P-Baeasure V-Valume Sdral gas Equation PV= MRT meles of gas R- Univessal Gas Constant 7-Temperatuse (0.0821 Latm kmat Past-A Smittial Phessure P values in Sdeal Gas quation P = RT Substituting 0.02 mol Xo.0821 Latmkmal215 k 2u30 L P = 0.196 atv 0.20 atm Newo conditions m=0.06 mol P 0.06 mol X0.0821 latm kmal x275 k 2-30 L O. 588 atm S 0.59 atm Pressure INCREASES With moles in DIRECT aposion

ncease m tempuatue New T = 80 k +215k-355 K P=MRT 0.02 mal X0.0821 latm kmel X355k 2030 L 0.25 atm Pressure INCREASES with tempesature in DIRECT Past B padartion MI=0.05 mol V, 0.09 L 2=0.08 mal 6 T 255 K P= 11. 80 atm We meed to calculate V PV = nRT (Sdeal gas quatien V=0.08 mol X 0.0821 Latm ktmolx255k V= MRT メ2 11.80 atw 0.14 L iTeropesature is increased to 355 K Now, 0.05mmal x 0.0821 Latm K mol X 355 1.80 atm V V=0.12 L