Notebooks sample calculations

Record in your notebook at least a sample calculation for each of these standardizations and all... 

Record the buret readings at the end points for all three beakers. Calculate the percent KHP in the sample for all three titrations and include at least a sample calculation in your notebook, along with all results and the average. Calculate the ppt relative standard deviation. If your three results do not agree to within 10.0 ppt relative standard deviation, repeat until you have three that do or until you have a precision satisfactory to you instructor. 

Calculate the molarity of your EDTA for each of the three titrations and calculate the average. Record in your notebook. Also calculate the parts per million CaC03 in the sample and compute the average. Record, as usual, in your notebook. 

A sample calculation should also be presented as an appendix to an undergraduate laboratory report. This appendix should show how one obtains tlie final results starting from the raw data. In general, the numbers used in the computations should have more significant fignres than are justified by the precision of the final result, in order to avoid mathematical errors due to roundoff. Units should be included with each step of the calculation. Also specify the source of raw data used (e.g., mn 5 on page 14 of notebook). 

The two deliverables from the field residue trial will be the samples, properly labeled, packed and shipped, and the field notebook, filled out correctly and completely. It is important that the Principal Investigator realize that all notations and calculations are made directly in the field notebook, not transcribed, and in ink. Multiple events, such as calibrations, applications, and harvests, must be documented on sequential individual forms. The field data in the notebook are not sent to the EPA as part of a submission package. These data must conform... 

Forensic analysis is usually required for the collection of data in the course of determining whether legislation has been infringed. The customer requires that, above all, there is an unbroken chain of evidence from the time the samples were taken to the presentation of evidence in courts of law. In the laboratory this will include documentation and authorization for sample receipt, sample transfer, sub-sampling, laboratory notebooks, analytical procedures, calculations and observations, witness statements and sample disposal. All of these aspects can be called as evidence in court. 

Notebooks/worksheets or other records show the date of analysis, analyst, analyte, sample details, experimental observations, quality control, all rough calculations, any relevant instrument traces and relevant calibration data. 

Compute the weights of your sample and precipitates from the data in your notebook The percentage of S03 in the unknown is calculated from these weights. Report the results to your instructor. 

This procedure does not take into account any absorbance due to the serum. If the serum is turbid, a correction should be made by measuring the absorbance at 510 nm of a 0.02-mL sample of blood serum in 3.0 mL of saline water. Read the A5W of this solution using saline water as blank. Record this reading in your notebook as Ac for correction. The calculation for cholesterol concentration will be described in the Analysis of Results. 

Add 1.0 mL of cholesterol enzymatic reagent to each cuvette, cover with hydrocarbon foil, and mix well. Incubate for 10-15 minutes at 37°C. Add 2.0 mL of saline water to each cuvette. Adjust spectrometer to zero with Blank and read Am for each sample. Record in your notebook for further calculations. 

In a modern laboratory, automated computer software for data acquisition and processing performs most of data reduction. Raw data for organic compound and trace element analyses comprise standardized calibration and quantitation reports from various instruments, mass spectra, and chromatograms. Laboratory data reduction for these instrumental analytical methods is computerized. Contrary to instrumental analyses, most general chemistry analyses and sample preparation methods are not sufficiently automated, and their data are recorded and reduced manually in laboratory notebooks and bench sheets. The SOP for every analytical method performed by the laboratory should contain a section that details calculations used in the method s data reduction. 

Laboratory records are kept very carefully in order to follow the progress of any study and to be able to repeat any steps that are necessary. Detailed records include all the information about samples, preparation methods, analysis results, and storage. These records provide the documentation necessary to prove that the research was done and how it was completed. All of this information together is data and there are two major places these data are kept a notebook and computer database. The Laboratory Notebook is an essential part of lab activities and the first record of all information. A laboratory notebook is needed to explain lab procediues, write down all lab data, show how calculations are made, and discuss the results of an experiment. A record of lab work is an important document, which will show the quantity and quality of the lab work that you have done. The laboratory database is the digital archive of information from the activities, experiments, and measurements of the laboratory. 

Calculate the percent of the original sample that is zinc. To do this, divide the mass of the zinc by the mass of the original sample and multiply by 100. Record the result in your notebook. 

Calculate the surface area of the original sample in cm2. The area of a rectangle is the length times the width. Remember that the zinc coating was on both sides of the sample, so the total area is length x width x 2. Record the result in your notebook. 

Also calculate the mass of zinc in milligrams per m2. To do this, convert the length and width of the steel sample to meters. Convert the mass of the zinc to milligrams. Calculate the area in m2 and divide the mass in milligrams by the area in m2. Record all results in your notebook. 

Include in your notebook the following data from both modes of calibration for each of the two metals, calculate the confidence limits at 95% probability using the Student s t-statistics for the ICV for both calibration modes. Report on the concentration of Pb in the coded unknown provided to you. Report on the Pb concentration of any unknown drinking water sample that you analyzed. Two statistical computer programs RSD and LSQUARES and written in BASIC are available for your use on the laboratory PCs. These programs are found in Appendix C. To use these programs, first download GWBASIC.exe on the contemporary Windows-based... 

Repeat this rinsing with two additional 0.5-mL portions of ice-cold water. Dry the crystals for 5-10 minutes by allowing air to be drawn through them while they remain on the Hirsch funnel. Transfer the product to a watch glass or a clay plate and allow the crystals to dry in air. It may take several hours for the crystals to dry completely, hut you may go on to the next step before they are totally dry. Weigh the crude product and set aside a small sample for a melting point determination and a color comparison after the next step. Calculate the percentage yield of crude acetaminophen (MW = 151.2). Record the appearance of the crystals in your notebook. 

Identify as many of the spots in your samples as possible. Determine which pigments were present in the yellow band and which were present in the green band. Draw a picture of the TLC plate in your notebook. Label each spot with its color and its identity, where possible. Calculate the Rf values for each spot produced by chromatography of the extract (see Technique 20, Section 20.9). At the instructor s option, submit the TLC plate with your report. 

Analysis Note the number of spots arising from each of the two original spots. Pay particular attention to the relative intensities of the two spots nearest the starting point in each of the samples these are syn-azobenzenes. Calculate the f -values of each of the spots on your developed plate. In your notebook, include a picture of the developed plate drawn to scale as a permanent record. Identify the solvent mixture that gave the best separation of syn- and anf/-azobenzene. 

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