Answered: 1) Suppose you use your calibrated…

1) Suppose you use your calibrated 25-mL pipet twice to deliver “50 mL" liquid, what is the actual total volume? What is the error in the final volume?

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter2: Basic Statistical Analysis With Excel

Section: Chapter Questions

Problem 4P

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The tolerance of a Class A 25 mL transfer pipet is +0.03 mL. A student uses an uncalibrated Class A transfer pipet to deliver a total of 125 mL of solution. What is the uncertainty in the delivered 125 mL? mL 0.15 Next, the student calibrates the pipet. The calibrated pipet delivers a mean volume of 24.995 mL with an uncertainty of +0.006 mL. The student then uses the calibrated 25 mL pipet to deliver a total of 124.975 mL of solution. What is the uncertainty in the delivered 124.975 mL? 0.375 mL Incorrect How does the uncertainty in the delivered volume using the calibrated pipet compare to the uncertainty in the delivered volume using the uncalibrated pipet? O The uncertainty in the delivered volume is the same for the calibrated and uncalibrated pipet. O The uncertainty in the delivered volume using the calibrated pipet is greater than the uncertainty in the delivered volume using the uncalibrated pipet. O The uncerainty in the delivered volume using the calibrated pipet is less…
10) The following results were obtained in an analysis of iron content in an ore sample. The results reported as % Fe for each analysis, were as follow: Samples no. 1 3 4 5 6 % Fe 20.10 20.50 18.65 19.25 19.40 19.99 i. Calculate the mean and median from the set of the data above ii. If the true value of %Fe is 19.65 %, calculate the value for absolute error and percentage relative error for sample no. 3 Using Q-test, justify whether an of the data must be rejected at 95 % ii. confidence level iv. Calculate the standard deviation and relative standard deviation of the data.
2) What is the relative error in delivering a volume of 18.28 mL from a class A 25 mL buret? (Remember, burets require two readings to deliver a certain volume, pipets only require one reading!) NIST Tolerances for Volumetric Glassware, Class Aa Tolerances (mL) Capacity (mL) (Less Than and Including) Volumetric Flasks Transfer Pipets Burets 1000 +0.30 500 ±0.15 100 +0.08 ±0.08 +0.10 50 ±0.05 +0.05 +0.05 25 +0.03 +0.03 +0.03 10 +0.02 +0.02 +0.02 5 +0.02 +0.01 +0.01 2 +0.006 "Corning Pyrex glassware and Kimball KIMAX, Class A, conform to these tolerances.
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The tolerance of a Class A 25 mL transfer pipet is +0.03 mL. A student uses an uncalibrated Class A transfer pipet to deliver a total of 125 mL of solution. What is the uncertainty in the delivered 125 mL? mL 0.15 Next, the student calibrates the pipet. The calibrated pipet delivers a mean volume of 24.995 mL with an uncertainty of +0.006 mL. The student then uses the calibrated 25 mL pipet to deliver a total of 124.975 mL of solution. What is the uncertainty in the delivered 124.975 mL? 0.375 mL Incorrect How does the uncertainty in the delivered volume using the calibrated pipet compare to the uncertainty in the delivered volume using the uncalibrated pipet? O The uncertainty in the delivered volume is the same for the calibrated and uncalibrated pipet. O The uncertainty in the delivered volume using the calibrated pipet is greater than the uncertainty in the delivered volume using the uncalibrated pipet. The unceWainty in the delivered volume using the calibrated pipet is less than…
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