![Principles of Instrumental Analysis](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_largeCoverImage.gif)
(a)
Interpretation:
The absolute and the relative uncertainty is to be determined for the measurement involving 600 count at 90% confidence level.
Concept introduction:
The standard deviation can be calculated as follows:
Also, the relative standard deviation can be calculated as follows:
The absolute uncertainty =
The relative uncertainty =
The formula for the confidence of counting intervals is −
(b)
Interpretation:
The absolute and the relative uncertainty is to be determined for the measurement involving 600 count at 95% confidence level.
Concept introduction:
The standard deviation can be calculated as follows:
Also, the relative standard deviation can be calculated as follows:
The absolute uncertainty =
The relative uncertainty =
The formula for the confidence of counting intervals is −
(c)
Interpretation:
The absolute and the relative uncertainty is to be determined for the measurement involving 600 count at 99% confidence level.
Concept introduction:
The standard deviation can be calculated as follows:
Also, the relative standard deviation can be calculated as follows:
The absolute uncertainty =
The relative uncertainty =
The formula for the confidence of counting intervals is −
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 32 Solutions
Principles of Instrumental Analysis
- How many of the following should be included in a good hypothesis? (i) A prediction of the results of the experiment (ii) A step-by-step walkthrough of how to do the experiment with specific references to amounts of reactants, glassware used, and other experimental details (iii) A summation of the data collected after doing the experiment, with comments on accuracy and precision if possible. (iv) A detailed list of chemicals that will be used (v) Waste disposal procedures (vi) A brief scientific explanation of the predicted results. Said another way, the hypothesis should include a scientific explanation of why the predicted results are expected. 1 2 3 4 5arrow_forwardRewrite the number 3.123 56 (+0.167 89%) in the forms (a) number (6absolute uncertainty) and (b) number (+percent relative uncertainty) with an appropriate number of digits.arrow_forward5-8. A method of analysis yields masses of gold that are low by 0.4 mg. Calculate the percent relative error caused by this result if the mass of gold in the sample is *(a) 500 mg. *(c) 150 mg. (b) 250 mg. (d) 70 mg.arrow_forward
- The pharmacist attempts to weigh 80mg of sodium carbonate on a balance having a sensitivity requirement of 4mg. Calculate the maximum potential error in terms of percentage.arrow_forward(a) Explain the difference between systematic and random errors. State whether the errors in (b)–(e) are random or systematic. (b) A 25-mL transfer pipet consistently delivers 25.031 + 0.009 mL when drained from the mark. (c) A 10-mL buret consistently delivers 1.98 6 0.01 mL when drained from exactly 0 to exactly 2 mL and consistently delivers 2.03 6 0.02 mL when drained from 2 to 4 mL. (d) A 10-mL buret delivered 1.983 9 g of water when drained from exactly 0.00 to 2.00 mL. The next time I delivered water from the 0.00 to the 2.00 mL mark, the delivered mass was 1.990 0 g. (e) Four consecutive 20.0-mL injections of a solution into a chromatograph were made (as in Figure 0-6) and the area of a particular peak was 4 383, 4 410, 4 401, and 4 390 units. (f) A clean funnel that had been in the lab since last semester had a mass of 15.432 9 g. When filled with a solid precipitate and dried thoroughly in the oven at 1108C, the mass was 15.845 6 g. The calculated mass of precipitate was…arrow_forward(a) For use in an iodine titration, you prepare a solution from 0.222 2 (+0.000 2) g of KIO3 [FM 214.001 0 (+0.000 9)] in 50.00 (+0.05) mL. Find the molarity and its uncertainty with an appropriate number of significant figures. (b) Would your answer be affected significantly if the reagent were only 99.9% pure?arrow_forward
- 2. Quantitative analysis student Analytical analyzed an ore sample for its lead content and obtained a mean of 4.75% Pb for five measurements. If the certified true value is 4.50%, what is the (a) percent error? (b) percent accuracy?arrow_forwardThe glucose concentrations in a patient with mildly elevated glucose levels were determined by a spectrophotometric analytical method and were recorded in mg/L as follows: 799, 745, 750, 774, 777, 800, 758 and the true value is 792. (a) Calculate the standard deviation (b) Calculate the relative error in ppmarrow_forward(b) The random error, r', on the result, R, is given by F = √()*² + ( )² R where v', and v, are the random errors on V', and Vt, respectively (1) Let V=26.00 mL, V = 24.00 mL; v' = ±0.01 (3) mL, vt = ±0.01 (2) mL. What is the percentage random error, r'/R x 100%, on R? (2) What is r'/Rx 100 if the conditions of each titration vary (e.g., different portions of the burette stem are used) so that V₁= 26.00 mL, V₁ = 24.00 mL; v' = ±0.05(2) mL, vt = ±0.04(8) mL?arrow_forward
- Assuming that you weighted a piece of silver five times and each time you got 52 grams. However, the actual weight from the Bureau of Standards said it should weigh 50 g. (a) What is the % relative errors? (b) What type of error does this exemplify? (c) Does this affect (a) reliability (b) Accuracy (c) both a & barrow_forwardIn a survey of 1000 large corporations, 250 said that, given a choice between a job candidate who smokes and an equally qualified nonsmoker, the nonsmoker would get the job (USA Today).(a) Let p represent the proportion of all corporations preferring a nonsmoking candidate. Find a point estimate for p.(b) Find a 0.95 confidence interval for p.(c) As a news writer, how would you report the survey results regarding the proportion of corporations that hire the equally qualified nonsmoker? What is the margin of error based on a 95% confidence interval?arrow_forwardA solution containing Cu2+ is analyzed by atomic absorption and gives an absorbance of 0.01000 units. The solution is spiked to increase the Cu2+ concentration by 2.000 mg/L and then gives an absorbance of 0.01613 units. (a) What is the concentration of Cu2+ in the solution (mg/L)? (b) The 1.000 mg/L solution of Cu2+ alone gave an absorbance of 0.00408 units; was the standard addition needed? Yes or Noarrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage LearningPrinciples of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305079113/9781305079113_smallCoverImage.gif)