CHM Lab 15: Counting by Measuring Mass



Counting by Measuring MassAre not 5 sparrows sold for 2 farthings, and not one of them is forgotten before God? Yea, the very hairs of your head are all numbered. Fear not therefore: you are of more value than many sparrows. Luke12:6-7Lab Report for: _______________________________TABLE 1 – Counting by Weighing Individual ObjectsItem DescriptionItem #MassCalculations12345Average:Std. Dev:% Variance:TABLE 2 – Counting by Weighing a Group of ObjectsMassCalculationsMass of 50 ObjectsAvg. Mass of 1 Object (from 50)Avg. Mass of 1 Object (from 5 individual values, Table 1 above)% DifferenceTABLE 3 – Summaryg/object (grams per single object)Avg. Mass [from group of 50; Table 2 above]Avg. Mass [from 5 individual values; Table 1 above]TABLE 4 – Predictions Using Average MassesMass of ~95%(g)Predicted Number[from Avg Mass Group of 50][Table 2]Predicted Number[from Avg Mass Group of 5][Table 1]Calculations:Actual Number:% Error:Hypothesize which data set will have the highest standard deviation from the average, and which will have the lowest (the one that samples 50 objects as a group, or the one that samples 5 objects individually?). Explain. Was your hypothesis correct? Why or why not? Explain.Describe in your own words what is meant by the concept “Counting by Weighing” or “Counting by Measuring Mass”. You have been asked by your boss to give 5000 of the objects that you used in today’s experiment to a customer. You do not actually count out 5000 objects but weigh out a certain mass that you are certain to a reasonable degree contain 5000 of the objects. What is the mass that you weigh to obtain 5000 of your objects? (Use the average having the lower % Error. Calculate below, show your work, circle your answer, include units.)You are in the business of selling paperclips. Without counting them individually, explain how you could use a balance (scale) to select 185 paperclips from a large bin of paperclips?One mole of the object used in today’s experiment would equal 6.02x1023 objects. Calculate the weight of 1 mole of objects using the best average mass you obtained in this experiment. Then, convert this number into tons (1 ton = 907,185 grams).Would it be practical to use the mole definition of 6.02x1023 to count visible objects by measuring mass? Explain your answer.In the introduction you learned that 1 mole of carbon = 6.02x1023 atoms of carbon which equals 12 grams. Compare the mass of 1 mole of carbon to the mass of 1 mole of paperclips. Why would we use the mole as a counting unit for atoms? ................
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