Lesson 5 Lab: Dilutions and the Potato Cannon
CIA Demonstration: Dilutions
The lab demonstration for dilution experiment involves the use of volumetric and serological pipettes during the lab demonstration because of the condition provided by the experiment (Stoker, 2010). The use of serological pipettes and the graduated cylinders helps in reducing the micro levels to number that is manageable. This means the absence of these two glassware will render the results of the experiment be false to the intended. The use of apparatus such graduated cylinder will result to the increase in the micro level.
The dilution experiment will start with the use of the liquid stock solution followed by taking the 15.0 mL solution with the use of a volumetric pipette. The solution is then taken to a volumetric flask of 500 Ml. performing a microbiology dilution will involve taking the serological pipette to help in measuring a volume of the solution stock then pouring it into a beaker. This is followed by adding the diluent (500 Ml buffer) using a graduated cylinder then mixing in the beaker. The most common diluents used in this process is buffer. The addition of diluents is followed by shaking the glass halfway in order to achieve mixing. The rest of the solution was gradually added using a dropper. The use of a dropper helps in ensuring there is accuracy in measurement. The final volume was read at the meniscus followed by addition of a magnetic stir bar to the final dilution then put on a stir plate for efficient mixing.
Precautions
Provided, during the experiment I go over the fill line, I would begin the experiment again rather than going on. This helps in ensuring accuracy of the results because of the nature of dilution. Dilution depend on the amount of the substance used hence the more amount of solution used will affect the results.
Dilution helps in cases where there is need to cut down on the concentration of a certain chemical (Stoker, 2010). This makes the process to be applicable, especially serial dilution which helps in cutting down on the concentration of microscopic organism. Further, serial dilution also helps in reducing the number of cells found in a sample.
Demonstration of potato cannon
The working of the potato cannon is under the principles of two gas laws, that is, Boyle’s law and the Charles’s law. Charles’s law states that provided the pressure and amount remains constant, the temperature of enclosed gas increases, while the volume also increases (Aneja, 2005). Boyle’s law states that provided the temperature and amount of gas remains constant the volume will be inversely proportional to the pressure of the gas (Aneja, 2005). This is because the working of the potato cannon works under the concept of pressure and volume whereby there is need to use a ramrod to push air that then launches the potato.
References
Aneja, K. R. (2005). Experiments in microbiology, plant pathology and biotechnology. New Delhi: New Age International.
Stoker, H. S. (2010). General, organic, and biological chemistry. Australia: Brooks/Cole Cengage Learning.
