Revised 1/08 SBIonic Compounds #1Note about experiment sequence - there are a limited number of laptops available in the lab. Some aspects of this experiment require the laptop, some do not. It may be necessary that you do various parts of the lab “out of sequence” relative to how they appear in the manual. As much as possible, complete one of the three activities before moving on to the next one. If you find it necessary to do the experiments out of sequence, spend some time considering your results when you are done to see how one part flows into the next.I. Visualization of Liquids and SolidsII. DissolutionIII. Dissolution ProductsIn this experiment, you will study the effect of increasing the concentration of ions on conductivity.IV. General Solubility RulesRevised 1/08 SBIonic Compounds #1Fundamentals and SolubilityThe goal of this lab is to help students better “imagine” what ionic crystalline compounds “look”like on the atomic scale, how these compounds dissolve in water, and what the products of thatdissolution process are (note: dissolution is a physical process, not a chemical reaction).The experiments are split into four activities:I. Visualization - model kits and the Atomic Microscope program are used to examineliquids, solids, crystals, and then ionic crystals in particular.II. Dissolution - web-based animations of the dissolution process will be used to guidediscussion about this process.III. Products of dissolution - the Vernier/Logger Pro system will be used (withconductivity probe) to explore the “macroscopic” scale results of dissolution.IV. Solubility properties – A large variety of ionic solids will be mixed with water todetermine compounds that dissolve and those that do not. Note about experiment sequence - there are a limited number of laptops available in the lab.Some aspects of this experiment require the laptop, some do not. It may be necessary that you dovarious parts of the lab “out of sequence” relative to how they appear in the manual. As much aspossible, complete one of the three activities before moving on to the next one. If you find itnecessary to do the experiments out of sequence, spend some time considering your results whenyou are done to see how one part flows into the next.I. Visualization of Liquids and Solids1) Use Atomic Microscope to explore liquids (which you may have examined earlier in the semester), solids, crystals, and ionic crystals.A) ClustersExperiment Group3D PlusExperiment Title Freeplay 3DAdd 3 Kr atoms. Turn on Interatomic Potentials, cool the temperature just a little above the coldest, speed up the program and wait for the 3 atoms to cluster.A.1) Which shape seems to be the most stable?Ionic#1-1If you were to add a fourth atom, what shape would you predict to form? A.2) What shape do you predict would be stable?Add a fourth Kr atom.A.3) Which shape does the program indicate to be the most stable?Now add 4 Ne atoms and control the simulation so that all eight atoms are clustered. Watch the atoms in the cluster vibrate and move around for a while to get a good idea of how they behave. Increase the temperature a bit and observe how the cluster comes apart.A.4) Describe the behavior of the cluster. Why do Kr and Ne atoms behave differently?Return to the Home menu and select Experiment “Sodium Chloride” from the “3D Plus” Group. Add 4 Na+ ions. Watch the atoms zip around for a bit. Now turn on Interatomic Potentials. A.5) What is happening? Why?Clear the display. Add 4 Cl¯ ions. Watch them for a while, turn on Interatomic potentials again and note the change in behavior and speculate as to what is happening.Don’t clear the display; instead add 4 Na+ ions. Control the temperature and program speed so that the atoms start to cluster. Continue to lower the temperature to just above its coldest, noting cluster shapes as you go.A.6) What shapes form? Speculate as to what drives the clusters to form?A.7) How is the atom motion and cluster shape different from the Kr/Ne cluster? Why? Ionic#1-2A.8) If you increase the temperature, how does the cluster break up? Why does it come apart in this fashion? Why don’t the Kr/Ne atoms behave this way?Ionic#1-3B) Formation of a SolidExperiment Group 3D PlusExperiment Title Freeplay (3D)Add 50 Kr atoms, turn on Interatomic potentials, and set program speed to ~1/2 and the temperature to the middle of the white zone. Let the simulation run until the atoms are in onecluster. B.1) What state has formed?Cool the cluster further (temperature slider under the “Classical Notation” icon).B.2) How does the behavior change? What specific changes are apparent compared to the state in B.1?The cluster that you have formed is a solid. Is this solid amorphous or crystalline? What is unique about crystalline solids?Click on the Information icon. Explore some of the prepared crystals here and observe their behavior as they are heated (note that rotating the 3D box is helpful in viewing the crystal). Then load the “172 Kr crystal” and note how atom motion changes with slight increases in temperature (keep the slider in the blue zone).B.3) Describe your observations. If this was a real crystal, what properties of the crystal would be changing?Ionic#1-4Now push the temperature slider to its hottest.B.4) What happens?Cool the temperature back down into the blue zone.B.5) Do you get a crystal back? Why or why not?Return to the Home menu and select Experiment “Sodium Chloride” from the “3D Plus” Group. From the Information menu (upper tool bar), load the 64 atom NaCl crystal.B.6) Sketch below how the ions are arranged in the crystal.When done, shut off the program (ESC key).2) Use the ICE model kits to build two different ionic compounds:C) NaCl (see p. 33 of the Solid State manual)Build the structure as described in the manual.C.1) Which spheres represent Na+ and which represent Cl¯? Explain your logic. NOTE: Thegeneral trend in atomic size does not apply here because these species are ions.C.2) Focusing on Na+, how many Cl¯ ions surround it?C.3) Focusing on a Cl¯, how many Na+ ions surround it?Ionic#1-5C.4) Can you see how you would build a 4th layer? Which ion(s) would comprise this layer?C.5) Imagine that you were to “cleave” a naturally occurring piece of NaCl crystal - would you expect that both types of ions would be present on the surface? Explain your thinking.D) CdI2