DIffusion & Osmosis Lab
DIffusion & Osmosis Lab DIffusion & Osmosis Lab
3. Place the egg on the balance, determine and record the dry mass of the egg.4. A corn syrup solution of assigned concentration will be made in a beaker:Group 1- 0% solution: 250 mL of waterGroup 2-10% solution: 25 mL corn syrup, 225 mL waterGroup 3-20% solution: 50 mL corn syrup, 200 mL waterGroup 4-30% solution: 75 mL corn syrup, 175 mL waterGroup 5-50% solution: 125 mL corn syrup, 125 mL waterGroup 6-70% solution: 175 mL corn syrup, 75 mL water5. Place the egg in the corn syrup solution and leave for 24 hours.6. Remove the egg from the corn syrup solution and dry off the outside of the egg with papertowels.HYPOTHESIZE: Predict what you think will happen during the experiment. (Think about whichbags will lose water and which will gain water.) Note your hypothesis in the passive voice, e.g.:“This will occur if…” NOT “I think this will occur…”7. Place the egg on the balance, determine and record the dry mass of the egg..DATA COLLECTION AND PROCESSING ASPECT 1: Recording Raw DataCreate a formal DATA TABLE in which to present the raw, unmodified data you collected. Be sure yourtable:o Is easy to understando Has a specific titleo Tables are titled in sequential order as “Table 1: title.” “Table 2: title”o Has column headingso Includes the unit of measurement of the MV and RV (always in metric units)o Includes the measurement uncertainty of the measurement tools used (or, if the data was a count,indicates that “counts have no measurable uncertainty”). Uncertainly is usually stated in a columnheading or as a footnote at the bottom of the table.o Has a consistent and correct number of digits for each measuremento Has decimal points aligning down a column (if applicable) and numbers centered in the columno Indicates which data was collected by which student IF the data was collected and pooled acrossmultiple students.Your report must include QUALITATIVE DATA. This might be a paragraph in which you describe thequalitative observations and results in general or be specific qualitative data for each trial that is presentedin table form.
LAB DRAWINGS are considered data by the IB Organization. Not all labs will include a lab drawing.However, when included, please be sure your lab drawings:o Are done with a sharp pencil line on white, unlined paper.o Have the drawing occupy at least half a page, centered on the page.o Include labels written off straight, horizontal lines to the right of the side of the drawing. The labelsshould form a vertical list.o Are accurate. Draw what you see; as you see it, not what you imagine should be there.o Include a title that states what has been drawn and what lens power it was drawn under. The titlemust be informative, centered, and larger than other text.o Has a scale that indicates how many times larger the drawing is compared to life size and a scale linethat indicates relative size.o Note that photographs are also accepted – must include labels, title and description.AS A CLASS: Design a data table… what should we include on our raw data table? Don’t forget units anduncertainties.8. Calculate the change in mass and percent change in mass. To calculate: percent change inmass = (final mass – initial mass)/initial mass. Than multiply by 100.9. Gather the data from the other groups in the class and find the class average for each baggie.DATA COLLECTION AND PROCESSING ASPECT 2: Processing Raw DataSTATISTICS are useful mathematical tools which are used to analyze data. Common statistics used inbiology are:o Meano Rangeo Mediano Percent changeo Standard deviation (to determine amount of variation around a mean)o T-test (to compare two means to determine if they are statistically different from each other). When at-test is calculated, you must indicate the significance level at which your critical T value isdetermined (we typically use the 95% confidence interval, 0.05).o Chi-square (to determine if “observed” results are significantly different from “expected” results)o Correlation coefficient (to determine the extent two variables are related to each other).Use only the statistical tests appropriate to investigate and address your problem question.For each statistic you calculate, you must EXPLAIN WHY YOU ELECTED TO DO THAT CALCULATION.What does the calculation tell you about the data?10. Construct a graph showing the percent change in mass versus the concentration of cornsyrup.Graph the results for both your individual data and class average on a graph. The independentvariable is on the X axis, and the dependent variable is on the Y axis.DATA COLLECTION AND PROCESSING ASPECT 3: Presenting Processed DataShow an EXAMPLE CALCULATION for each statistic you calculate. Use plenty of room; make sure they arelabeled, are clear and are legible. Show the units of measurements in all calculations. Pay attention to thenumber of digits! Don’t lose accuracy by carelessly rounding off. Round only at the end of a calculation. Donot truncate.Present your data processing results in a TABLE. The initial raw data and the processed (calculated) datamay be shown in one table provided they are clearly distinguishable. Be sure your processed data table:o Is easy to understando Has a specific titleo Has column headingso Includes the unit of measuremento Has a consistent and correct number of digits for each measurement (to the same precision as yourraw data)
3. Place the egg on the balance, determine and record the dry mass of the egg.4. A corn syrup solution of assigned concentration will be made in a beaker:Group 1- 0% solution: 250 mL of waterGroup 2-10% solution: 25 mL corn syrup, 225 mL waterGroup 3-20% solution: 50 mL corn syrup, 200 mL waterGroup 4-30% solution: 75 mL corn syrup, 175 mL waterGroup 5-50% solution: 125 mL corn syrup, 125 mL waterGroup 6-70% solution: 175 mL corn syrup, 75 mL water5. Place the egg in the corn syrup solution and leave for 24 hours.6. Remove the egg from the corn syrup solution and dry off the outside of the egg with papertowels.HYPOTHESIZE: Predict what you think will happen during the experiment. (Think about whichbags will lose water and which will gain water.) Note your hypothesis in the passive voice, e.g.:“This will occur if…” NOT “I think this will occur…”7. Place the egg on the balance, determine and record the dry mass of the egg..DATA COLLECTION AND PROCESSING ASPECT 1: Recording Raw DataCreate a formal DATA TABLE in which to present the raw, unmodified data you collected. Be sure yourtable:o Is easy to understando Has a specific titleo Tables are titled in sequential order as “Table 1: title.” “Table 2: title”o Has column headingso Includes the unit of measurement of the MV and RV (always in metric units)o Includes the measurement uncertainty of the measurement tools used (or, if the data was a count,indicates that “counts have no measurable uncertainty”). Uncertainly is usually stated in a columnheading or as a footnote at the bottom of the table.o Has a consistent and correct number of digits for each measuremento Has decimal points aligning down a column (if applicable) and numbers centered in the columno Indicates which data was collected by which student IF the data was collected and pooled acrossmultiple students.Your report must include QUALITATIVE DATA. This might be a paragraph in which you describe thequalitative observations and results in general or be specific qualitative data for each trial that is presentedin table form.
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