Molarity & Saturation Virtual Lab

Sergio De La Paz Name __________________________________ Molarity and Saturation Virtual Lab Pre-lab: To complete questions 1-4, you may need to refer to your notes, book, or a website. In the boxes below, draw what you see if your solution is unsaturated, saturated, and supersaturated. Unsaturated Saturated Supersaturated 1. What are the different ways to measure concentration of a solution and give an example of when Concentration can be measure with molarity, molality, and mass each one is used. _______________________________________________________________ percent. Molarity is used in a given volume. Molality is used with colligative ______________________________________________________________________________ properties. Mass percent can be used for consumer products. ______________________________________________________________________________ 2. Compare and contrast dilute and concentrated to unsaturated, saturated, and supersaturated. Use pictures if that is helpful for you. ____________________________________________________ Dilute and concentrated refer to the relative amount of solute in a solution, while ______________________________________________________________________________ unsaturated, saturated, and supersaturated describe the state of the solution in ______________________________________________________________________________ relation to the solute's solubility at a given temperature. ______________________________________________________________________________ 3. What changes could be made to a solution in order to increase concentration? _______________ You can add more solute or remove some of the solvent. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 4. What are the factors that allow you to increase the dissolving rate? _________________________ Increasing the temperature, stirring the solution, and decreasing the particle size ______________________________________________________________________________ of the solute. Lab: 1. Access your computer. Open a browser and go to https://phet.colorado.edu/en/simulation/molarity 2. Click the box next to “show values”. 3. In this simulation, we are assuming that the temperature is set at 25°C and stays constant. 4. Set the volume to 0.50 L using the slider. 5. Use the drop down box at the bottom to change the solute that will be mixed into the water. 6. Use the “amount” slider to change the concentration of the solution. 7. Record the number of moles needed to reach saturation (try to get the least amount of moles for saturation . . . only 1 or 2 squares (particles) when “Saturated” first shows up on the beaker) for each solute if saturation can be achieved at 0.50 L. If saturation cannot be achieved at 0.50 L, Sergio De La Paz Name __________________________________ decrease the volume until saturation is achieved and record it. **Not all solutes can reach saturation. 8. Calculate the number of grams needed for each saturation point. Data: Substance Moles Volume Molarity Grams Drink Mix 1.0 mol 0.2 L 5.0 M N/A 182.943 g Cobalt (II) nitrate 1.0 mol 0.2 L 5.0 M Cobalt (II) chloride 0.871 mol 0.2 L 4.35 M 113.089 g 30.006 g Potassium dichromate 0.102 mol 0.2 L 0.5 M Gold (III) chloride 0.456 mol 0.2 L 2.25 M 138.318 g Potassium chromate 0.672 mol 0.2 L 3.35 M 130.495 g Nickel (II) chloride 1.0 mol 0.2 L 5.0 M 129.599 g Copper (II) sulfate 0.29 mol 0.2 L 1.4 M 46.286 g Potassium permanganate 0.102 mol 0.2 L 0.5 M 16.119 g Calculations (show an example of 1 calculation): Cobalt (II) chloride 129.839 g/mol x .871 mol = 113.089 g. Questions: 1. If saturation could be reached, give one variable that could be changed in order to make the Add more of the solvent. solution unsaturated. ____________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 2. Could any of the solutions be made into a supersaturated solution? If not, why? _______________ No, some of the solutions could not be made into a supersaturated solution. I think ______________________________________________________________________________ this is because of the way the solute behaves within its conditions in the solvent. ______________________________________________________________________________ ______________________________________________________________________________