[iii] (1 pts.) a supersaturated solution Answer: When solute is added to supersaturated solution it will be impossible to dissolve since it is more concentrated than a saturated solution. (d) (2 pts.) What is the role of vacuum filtration in this process of Recrystallization? How do you do it? Be detailed and specific, and include all steps. Answer: The role of vacuum filtration in recrystallization it to purify the sample further once it has crystallized. 1: you turn on the vacuum, wet the filter paper, and collect crystals in the filter. 2: wash the crystal with water, cold water, to clean off its colors, making it almost colorless. (e) (2 pts.) Suppose we are dealing with calcium chloride as opposed to the chemical in the video. If a solution contains 70 g of calcium chloride per 100 g of water at 25 degrees Celsius, is the solution unsaturated, saturated, or supersaturated? Explain your answer. You may want to refer to Figure 13.4 in your text for help, or perhaps refer to the image at .. Answer: CaCl2 is saturated at 74.5/100mL (20 degrees C). In the problem, the room temperature increased, when room temperature increases so does the solubility curve. The temperature is 25 degrees Celcius, the saturation point is 74.5 which will be passed; the solution is now supersaturated at 25 degrees C at 70/100 g concentration. The solubility curve is CaCl2 is above NaCl. Anything above this line is supersaturated and below the line is unsaturated. Since we have 70/100 gm water the solution is unsaturated. DON'T FORGET TO INCLUDE REFERENCES IN ORDER TO FULLY DEVELOP YOUR ANSWERS AND GO BEYOND THE BASICS OF THE QUESTION!!!
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- Spring '13
- Polymer, Calcium Chloride, adipoyl chloride, supersaturated