Serial dilution from econ 101 at institute of chemistry ceylon. Dilution and concentration theory dilution and concentration theory sounds ominous but you use dilutions and concentrations fairly frequently outside of your scientific life. Key is licensed under a creative commons attributionnoncommercialsharealike 4. Solutions can be diluted by removing a known amount from a solution of known concentration and mixing it with an amount of solvent to reestablish the original volume.
The organization, accuracy, completeness, interest in topic, results and explanations determine report grade. How to perform serial dilutions in microbiology duration. Serial dilutions are widely used in experimental sciences, including biochemistry, pharmacology, microbiology, and physics. Using a turntable and sterile bent glass rod see fig. A dilute solution contains only a small amount of solute in a given amount of solution, while a concentrated solution contains a large amount of solute in a given amount of solution. Typically, the dilution factor remains constant for each dilution, resulting in an exponential decrease in concentration. While you may already make solutions in the lab by following recipes, we hope this webinar will help you understand the concepts involved so that you can. Each student might be required to turn in a separate lab report, but they are. Serial dilution is a series of dilutions used to determine the concentration or titer of a substance. Pdf lab report of microbiology akbar haqi academia. Feb 17, 2015 this pin was discovered by biology 4u. Serial dilution is the stepwise dilution of a substance in solution. Dilution adina fromowitz department of chemistry and biochemistry, queens college cuny.
Serial dilution to begin, you must know how to calculate dilution. This procedure is repeated until the desired concentration is reached. Dilutions of solutions introduction to chemistry lumen learning. In this lab, a serial dilution will be made of a sample of bacteria, and then those dilutions will be used to culture bacteria in order to estimate their numbers. This results in a solution of a molarity proportional to the amount removed divided by the total volume. Here is an example of a lab report that was actually submitted and received a perfect grade along with stepbystep instructions on writing an effective lab report. View lab report lab report 8 from chem 1 at brooklyn college, cuny. We will run through an example where multiple dilutions are needed and we need to. Serial dilutions are used to accurately create highly diluted solutions as well as solutions for experiments resulting in concentration. Dilution calculations from stock solutions in chemistry.
The format of the report is that of a journal submission. Freida zavurov abstract in this experiment the molar concentration of a sodium hydroxide solution predicted from the dilution equation, was compared to the concentration determined from the ph level of the solution. Repeated serial dilutions will be necessary to determine accurate concentration. A serial dilution is a series of sequential dilutions used to reduce a dense culture of cells to a more usable concentration. These flasks range in size from 10 ml to 2000 ml are are carefully calibrated to a single volume. The precise mass of solute is dissolved in a bit of the solvent and this is added to the flask. If youre working in a chemistry lab, its essential to know how to calculate a dilution. Apr 16, 2012 this feature is not available right now. Review of dilution, concentration, and stock solutions a dilution is a solution made by adding more solventto a more concentrated solution stock solution, which reduces the concentration of the solute. Draw 1 ml of undiluted solution from test tube us with a pipette and transfer it to the test tube labeled 1.
Serial dilution procedure diagram medical laboratory. A serial dilution is a dilution where a series of dilutions are conducted, each one may be onetenth as concentrated as the previous. A dilution is prepared by adding a specific amount of a concentrate to water to obtain a new volume and concentration. In homeopathy, serial dilutions called potentisation are often taken so far that by the time the last dilution is completed, no molecules of the original substance are likely to remain. For the solutions to be usable in the lab for a titration, for instance, they must. Sample chem217 laboratory reports formal report format. Review of dilution, concentration, and stock solutions a dilution is a solution made by adding more solvent to a more concentrated solution stock solution, which reduces the concentration of the solute. Upon completion of this lab, the student should be able to proficiently calculate molarities for solutions. The ability to make dilutions is essential to working in biology, chemistry, cooking. What are serial dilutions chemical calculations chemistry. This video shows creation of a series of solutions of different ph by serial dilution. In the experiment lab students will be diluting environmental toxins to see their effect on fertilization and development.
Even on this basic laboratory experiment requires of those standard obligations. To prepare a standard solution a piece of lab equipment called a volumetric. In this lesson an attempt has been made to relate dilution to the real world. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. Serial dilution many procedures performed in modern biology and chemistry laboratories require sets of solutions that cover a range of concentration s. This webinar is intended to give a brief introduction into the mathematics of making solutions commonly used in a research setting. Calculating concentrations based on dilution factors.
Molarity moles of soluteliters of solution a solution is the mixture of 2 or more substances in the same phase. Introduction it is difficult to know and imagine the size of microorganisms, since they are too small to. A serial dilution is a series of stepwise dilutions, where the dilution factor is held. Dilutions and concentrations introductory chemistry 1st.
Nov 15, 2016 serial dilutions are really useful in chemistry, microbiology, medicine amongst other things. Estimation method for serial dilution experiments sciencedirect. Often it is convenient to prepare a series of solutions of known. Dilution adina fromowitz department of chemistry and biochemistry, queens college cuny chem 1. Preparing dilutions is a common activity in the chemistry lab and elsewhere. Serial dilution is a method of dilution that is constantly repeated until the desired concentration is met. Acids and bases usually come in concentrated form, as concentrates, but they are rarely used in this form. Hopfully when going into the lab, you are able to know the following skills. Fifth video in a series of videos discussing concentration calculations commonly used in a laboratory.
Scribd is the worlds largest social reading and publishing site. Serial dilutions are commonly used in microbiology where the solution being diluted contains bacterial colonies. Creating solutions of standard molarity lab report. How to perform serial dilutions learn how to use serial dilutions to cover a range of experimental concentrations or enumerate bacteria in this simple infographic. Anmol patel the university of oklahoma chemistry 1415 11 february 2019 dilution is the solution pre lab. Preparation of a stock solution of chromium iii nitrate. Serial dilutions involve diluting a stock or standard solution multiple times in a row. This is the first lab report required for the first general chemistry lab at uncc. To make our dilution we would use 200ul of serum and 200 ul, or 800 ul of water.
Lab example for concentration and dilution youtube. These include quantifying the number of bacteria in a sample using plate counts and the development of standard curves for quantitative colorimetric, radiometric, and enzymatic assays. We will run through an example where multiple dilutions are needed and we need to calculate the final. Solute is the dissolved substance and a solvent is the dissolving medium. Because of this, a variety of methods have been developed. Many procedures performed in modern biology and chemistry laboratories require sets of solutions that cover a range of concentrations. Standard obligations in laboratory experiments such as preciseness in calculating and measuring numerous substances, as well as meticulousness are undoubtedly vital. However, the numbers of microorganisms in a given sample are required to know in certain aspect such as dairy industries, diseases investigation, and so on. Prior to the lab, you will also need to complete your prelab report, which will test your understanding of the following concepts. Once organism is diluted out by certain dilution factor, it is allowed to inoculate on suitable nutrient media in petri dished. The easiest method is to make a series of 1 in 10 dilutions.
Experiment x3 of the chemistry 217 lab manual 1995, pp. For example, a tenfold serial dilution could result in the following concentrations. The instrument we are going to run this test on needs at least 1 mlul of fluid to run the test so how shall we make this dilution. Lab report 8 dilution adina fromowitz department of. Check out a chemistry or science journal to see how the report should be written. Serial dilution lab in this unit we will be discussing measurements of concentration that us e both very big and very small numbers. This exercise is intended to familiarize us with using scientific notation to express big and small number easily and the process of using serial dilutions to make concentrations of known values. Dilution is a decrease in a solutions concentration, whereas concentration is an increase in a solutions concentration.
For example, when you are making orange juice from a frozen concentrate, you mix 1 can of concentrate with 3 cans of water. They will need to understand dilution in order to be able to do these experiments in any kind of meaningful way. A dilution in chemistry is a process that reduces the concentration of a substance in a solution. Spec20 serial dilution lab free chemistry materials. Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. An example of a dilute solution is tap water, which is mostly water solvent, with a small amount of dissolved minerals and gasses solutes.
In order to obtain a certain concentration of acid or base, dilutions are made. Usually the dilution factor at each step is constant, resulting in a geometric progression of the concentration in a logarithmic fashion. Mass per unit volume is often used to report the concentration of proteins and. The dilution of a sample in a diluent the liquid used. Creating solutions of standard molarity lab report studocu. Preparing and diluting solutions lab introduction the amount of solute that is dissolved in a given quantity of solvent is called the concentration of the solution.
To prepare a standard solution a piece of lab equipment called a volumetric flask should be used. Lab reports can also be written for college classes, as well as other professional areas including engineering and computer sciences. Molarity, dilutions, and preparing solutions lab r. Serial dilutions are really useful in chemistry, microbiology, medicine amongst other things. Lab math solutions, dilutions, concentrations and molarity. Serial dilution is one of the core foundational practices of homeopathy, with succussion, or shaking, occurring between each dilution. This particular video shows the basics behind setting up and calculating a serial dilution. Introduction microorganism is an organism that is microscopic or submicroscopic, which is too small to be seen under naked eyes. Preparing and diluting solutions lab fhs ap chemistry. Jan 27, 2020 the libretexts libraries are powered by mindtouch and are supported by the department of education open textbook pilot project, the uc davis office of the provost, the uc davis library, the california state university affordable learning solutions program, and merlot.
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