Diffusion and Osmosis
Preparation of Solutions for the Agar Cube Experiment ExpandIMPORTANT: Wear gloves, goggles, and appropriate personal protective equipment - chemicals can be hazardous at high concentrations. For the diffusion indicator solution, weigh out 1 g of phenolphthalein and add it to a beaker containing 100...
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| Idioma: | Inglés |
| Publicado: |
Cambridge, MA :
MyJoVE Corp
2016.
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| Colección: | JOVE Science Education.
Lab Bio. |
| Acceso en línea: | Acceso a vídeo desde UNAV |
| Ver en Universidad de Navarra: | https://innopac.unav.es/record=b42110798*spi |
| Sumario: | Preparation of Solutions for the Agar Cube Experiment ExpandIMPORTANT: Wear gloves, goggles, and appropriate personal protective equipment - chemicals can be hazardous at high concentrations. For the diffusion indicator solution, weigh out 1 g of phenolphthalein and add it to a beaker containing 100 mL of 95% ethanol. To make the basic solution for the agar, measure 80 mL of water into a beaker, and then add 0.4 g of NaOH. Stir until the solute is dissolved then bring the total volume of the solution to 100 milliliters to make a 0.1 molar solution. To make the diffusing acid, measure out 25 mL of HCl and add it to 475 mL of water. NOTE: Plan to make around 500 mL of this HCl solution per work group. Preparation of Agar with Phenolphthalein ExpandIMPORTANT: Agar needs time to cool, so prepare several hours in advance of the class. To prepare the agar, first weigh out 20 g of dehydrated agar powder and then add this to 1 L of water. Heat the solution to near boiling or until it becomes fully clear. Then, cool the agar to 55 °C and add 10 mL of the phenolphthalein ethanol solution. Slowly add the 0.1 molar sodium hydroxide solution to the agar until it becomes vibrant pink. Take a clean tray with deep sides and pour the agar to a depth of 3 cm. Place the tray into the refrigerator for a few hours. Preparation of Dialysis Tubing and Solutions ExpandTo prepare the 1% starch solution, weigh out 10 g of soluble starch and add it to 500 mL of distilled water set on a magnetic stir plate. When the solute has dissolved, bring the final volume of the solution up to 1 L with more water. To prepare 1M NaCl, dissolve 58.4 g of NaCl in 500 mL of distilled water, in a 1 L container. Then, bring the volume up to 1 L with distilled water. To prepare 1M dextrose, add 180.2 g of dextrose powder to 500 mL of distilled water in a 1 L beaker. Once dissolved, bring the volume up to 1 L with distilled water. Cut the dialysis tubing into 20 cm pieces. Place the pieces to soak in distilled water; make sure they are kept moist at all times. NOTE: Excess tubing can be stored at 4 °C in 20% ethanol to prevent bacterial growth. |
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| Notas: | Tít. sacado de la página de descripción del recurso. |
| Descripción Física: | 1 recurso electrónico (175 seg.) : son., col |
| Formato: | Forma de acceso: World Wide Web. |
| Público: | Para estudiantes universitarios, graduados y profesionales. |
