LAB WRITE UP - Mr. Ciardullo's Class Webpage



LAB WRITE UPLAB WRITE UP EXAMPLEAbstractFrom our previous experiment, we examined how many drops a penny can hold - and in our studies, we noticed that the tails side held more drops than the heads side. ?We feel that the main reason was that one of our?colleagues?held the dropper either?closer or further from the penny. ?In this experiment, we examine how height (independent variable) affects the number of drops a penny can hold (dependent variable). ?My hypothesis is that by increasing the height of the dropper, the drops will go down based on the idea that as you increased height, you also?simultaneously?increase the drops speed due to gravitational?acceleration via gravitational potential energy. ?The experimental results?confirmed?my hypothesis by showing the decrease of drops the penny can hold as we increased height. ?Experimental Question and Hypothesis:Question: How does salt affect the number of drops of water a penny can holdHypothesis: If I add 10g of salt to 200 mL of water, then the number of drops a penny can hold will go down because as the salt slips in between the water molecules, this may disrupt the cohesive strengths of water. ?Also, due to the strong polar nature of salt molecules when dissolved, water may have a harder time sticking to each other, making adhesion possibly a stronger force than cohesion while in solution. ?Experimental Design:To test this, dissolve 10g of salt into 200mL of water and test to see how many drops of salt water a penny can hold and compare it to the amount of drops of regular water a penny can hold.Materials:10g Salt2 beakers each containing 200mL of waterStirring Rodpenny2 pipette droppersProcedures:Fill up both beakers with 200mL of waterMeasure out 10g of saltPlace the salt into one of the beakers of water and stir till dissolved.You should have one beaker of clean water and another with salt water.Place a clean penny on the table.Fill the dropper with the salt water solution.Place drops of salt water on the pennyCount the number of drops the penny can hold before it spills over the edge.Record the number of drops in the data table.Repeat the trial 5 times for the salt water solution and for the clear water.After recording 5 trials each, take the average of each solution.ObservationsWe noticed that as we conducted our experiment, the clear water had larger drops than the salt water drops - for reasons we’re not sure.We also noticed that on our third clean water trials, we had an extremely large number of drops.We also noticed that the dropper after the experiment had salt crystals forming outside the pipette/dropper.LAB WRITE UP ELEMENTSAbstract:The abstract is an overview of your whole experiment from start to finish.Includes either outside claims, personal insight, background research, or previous experiments that may have prompted the research or experiment in the first place.The independent and dependent variables are clearly identifiedThe hypothesis is also clearly statedThe hypothesis has also been tested?The concluding statement of?confirming?or rejecting is also clearly stated with a reason to back it up.Experimental Question & Hypothesis:Question (More focused & restated)Hypothesis (More focused & restated)If I change my (independent variable), then my (dependent variable) will change because... (provide the possible explanation for a set of observations here).Experimental Design:Brief statement explaining the overall experimentWhat materials will you need.Be very specific with the quantities included.Under procedures - list specifically your step by step process you plan on carrying out your experiment.Observations:List some things you noticed during the experiment. ?List things that you saw, smelt, felt - or whatever phenomenon you witnessed during or after your experiment.Data Collection and further observations:Organize your numerical data that reflects your experimentTrials are usually the furthest on the left, followed by the control, then any independent / changed variable towards the right. ?For instance, my water is the control - it's the one that I'm comparing everything to. ?The salt is the independent variable?that I'm comparing to the water. ?The average in this case, is what I'm more interested in, thus when I create a graph below, I only use the averages.Data Analysis:Our data shows that the pure water out performed the salt solution by nearly 2:1 on average.Our range of data for water ranged from 36-52Most of the numbers were in the mid to upper 40’s.The 36 drops seems a little out of the ordinary.52 drops may seem to be a little high.Our range of data for the salt water solution ranged from 21-25.The numbers are closely clustered together.Conclusion:In our research, we were investigating how salt affects the cohesive properties of water. ?To test this, we were using the number of drops a penny can hold as our indicator for cohesiveness after we added salt to the solution. ?According to our data, by adding salt to the water seemed to affect the cohesive properties of the water, as indicated by the severe reduction of the number of drops the penny would hold. ?We were not too surprised with our findings. ?We did notice some anomalies during our experiment, however. ?For instance, we did notice that we have a wide range of drops with the pure water solution, which ranged from 36-52. ?We think the lower number is more of the exception than the rule - as we noticed that the next number in series was closer to the higher number than the lower number. ?We think it might be because as we dropped the water, the drops may have been slightly bigger, or the drops touched the puddle on the penny, which reduced the number of drops. ?If we were to run this test again, we need to increase the height the drops that were administered to ensure that the drops don’t come in contact with the puddle while the water is still being formed from the pipet.?The salt water solution, however, has a much tighter range of data - only having a four point difference and each of them in the lower to mid 20’s.What this means is that our hypothesis is thus far correct - in that the salt disrupts the cohesive properties of water. ?We still think that the reason the salt disrupts the cohesive property of water is due largely in part to the salt molecules slipping in between and separating the water molecules. ?We do know that water is polar and the salt becomes ionic when dissolved in water (Ophardt, 2003). ?Perhaps the adhesive attraction that water has with the salt is stronger than the cohesive property of water (Freeman, 2007). ?Further testing would be needed to suggest such a hypothesis by possibly using magnets or some other device with positive and negative charges to see how it affects the polarity of water & salt.Data Analysis:Make some basic observations that you noticed in your numbers and graph.Make some basic observations with trends you may see, the range of data, high/low numbers, where are most of the numbers clustered together etc.Conclusion:Summarize your question & hypothesisSummarize your overall proceduresSummarize your observations & data analysisDiscuss any possible experimental errors along the way and?how this may have impacted your results.Answer your question.Address your hypothesis - Did your data prove or disprove your hypothesis as being correct?What did you learn from your findings?What other questions developed as a result of your experiment - how would you go about furthering your research?ReferencesPerlman, H. (March 17, 2014) “Adhesion & Cohesion of Water” <; Last Retrieved August 18, 2014Ophardt, C. (2003) “Solubility of Salts” Virtual Chembook, Elmhurst College <; Last Retrieved September 9, 2014Freeman, S. (October 18, 2007) “How Water Works” <; Last Retrieved August 18, 2014Author Last, F. (Date Published) "Title of the article written" Publisher Source <full? ................
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