knot ress cor Hi Deaum The molarity of a NaOH solution was determined by titration with KHP. The results of five titrations were 0.1025 M, 0.1087 M, 0.1100 M, 0.1052 M, 0.0997 M. Answer the following questions based on 95% confidence level. d) Calculate the relative standard deviation of the concentration of NaOH. e) Calculate the standard error of the concentration of NaOH. f) Calculate the confidence interval of the concentration of NaOH. Report your answer with appropriate significant figures. g) If the true concentration of this NaOH solution is 0.1045 M, is the sample mean significantly different from the true concentration? h) Another student also measured the concentration of the same NaOH solution. The result of the three titrations were 0.1028 M, 0.1012 M, 0.0983 M. Are the mean concentrations from the two students' result similar to each other? Hint: you need to do a student's t test and a F test.

knot ress cor Hi Deaum The molarity of a NaOH solution was determined by titration with KHP. The results of five titrations were 0.1025 M, 0.1087 M, 0.1100 M, 0.1052 M, 0.0997 M. Answer the following questions based on 95% confidence level. d) Calculate the relative standard deviation of the concentration of NaOH. e) Calculate the standard error of the concentration of NaOH. f) Calculate the confidence interval of the concentration of NaOH. Report your answer with appropriate significant figures. g) If the true concentration of this NaOH solution is 0.1045 M, is the sample mean significantly different from the true concentration? h) Another student also measured the concentration of the same NaOH solution. The result of the three titrations were 0.1028 M, 0.1012 M, 0.0983 M. Are the mean concentrations from the two students' result similar to each other? Hint: you need to do a student's t test and a F test.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

ChapterA1: Evaluation Of Analytical Data

Section: Chapter Questions

Problem A1.22QAP

See similar textbooks

Similar questions

SCE students measured the concentration of HCl in a solution by titrating with different indicators to find the end point.Indicator Mean HCl concentration (M)(± standard deviation)Number of measurementsBromothymol blue 0.09565 ± 0.00225 28Methyl red 0.08686 ± 0.00098 18Bromocresol green 0.08641 ± 0.00113 29Is the difference between indicators 1 and 2 significant at the 95% confidence level? Answer the same question for indicators 2 and 3
A solution of Ba(OH)2 was standardized against0.1215 g of primary-standard-grade benzoic acid, C6H5COOH (122.12 g/mol). An end point was observedafter addition of 43.25 mL of base. (a) Calculate the molar concentration of the base. (b) Calculate the standard deviation of the molarconcentration if the standard deviation for themass measurement was ±0.3 mg and that for thevolume measurement was ±0.02 mL. (c) Assuming an error of ±0.3 mg in the mass measurement,calculate the absolute and relative systematicerror in the molar concentration.
The thiourea (NH2)2CS in a 1.600 g sample of an unknown organic material was extracted into a dilute acid solution and was titrated with 42.50 mL of 0.0010 M Hg2+. Equation: 4 (NH2)2CS + Hg2+ → [(NH2)2CS]4Hg2+ Find the percentage thiourea present in the sample.
A 50.00 (±0.03) mL portion of an HCl solution required 29.71(±0.03) mL of 0.01963(±0.0030) M Ba(OH)2 to reach an end point with bromocresol green indicator. The molar concentration of the HCl is calculated using the equation below (attached image): a.) Calculate the uncertainty of the result (absolute error). M=0.02333(±?????) M b.) Calculate the coefficient of variation for the result. CV= (Sy/y) x 100%
The thiourea in a 1.455 g sample of organic material was extracted into a dilute sulfuric acid solution and titrated with 37.31 mL of 0.009372 M Hg2+ via reaction: 4(NH2)2CS + Hg2+ →[(NH2)2CS]4 Hg2+ P.S. Answer only the last two letters of the following questions. (Only C and D) a. Is this an example of total analysis technique or concentration technique? Explain. b. Calculate the percent (NH2)2CS ( 76.12 g/mol) in the sample. c. What is classification of the analysis based on the amount of sample and amount of analytes present? Explain. d. If the true value is 10.00%, calculate the absolute and relative error.
1. 1093-g sample of impure Na2CO3 was analyzed by residual precipitimetry. After adding 50.00 mL of 0.06911 M AgNO3, the sample was back-titrated with 0.05781 M KSCN, requiring 27.36 mL to reach the endpoint. The percentage Na2CO3 (MW = 106.0 g/mole) in the tested sample is ________ % ? Note: Express final answer using least number of significant figures. 2. The alkalinity of natural waters is usually controlled by OH- (MW = 17.01 g/mole), CO3-2 (MW = 60.01 g/mole), and HCO3- (MW = 61.01 g/mole), which may be present singularly or in combination. Titrating a 10.0-mL sample to a phenolphthalein endpoint requires 38.12 mL of a 0.5812 M solution of HCl, and an additional 18.67 mL of the same titrant to reach the methyl orange endpoint. The composition of the sample is _________% CO3-2 and ___________ % OH- Note: Express final answers using least number of significant figures.
A student performs three titrations in order to standardize a NaOH solutions. The results are: 0.105 M, 0.0990 M, and 0.110M. Calculate the average and the standard deviation. Are the results acceptable, or should she perform more titration
A 10.00mL sample of alcoholic ethyl acetate was diluted to 100.00 mL. 20.00 mL was aliquoted and mixed with 40.00 mL of 0.04672 M KOH. The resulting mixture was heated for 2 hours. CH3COOC2H5 + OH- → CH3COO- + C2H5OH After cooling, the excess OH was back titrated with 3.41 mL of 0.05042 M H2SO4. Answer the following: Calculate the number of moles of OH- that reacted with ethyl acetate. Calculate the number of moles of ethyl acetate in the 20.00 mL solution. What is the mass of ethyl acetate (FW=88.11 g/mol) in the original 10.00 mL sample?
Based on the analysis of a vinegar solution via titration with 0.1 M NaOH. Results are as follows: Trial 1 Volume of vinegar solution used (mL) 5.00 Final burette reading (mL) 44.20 Initial burette reading (mL) 0.00 Determine the percentage mass of acetic acid in vinegar for Trial 1. The density of vinegar is 1.01 g/mL and molecular mass for acetic acid is 60 g/mol.
Aspirin powder = 0.8110g MW of Aspirin = 180g.mol-1 Volume of 0.5N HCl consumed in back titration = 23.50mL Volume of 0.5N HCl consumed in blank titration = 44.50mL Percent purity (USP/NF) = Aspirin tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of aspirin (C9H8O4) What is the calculated weight (in grams) of pure aspirin?..
help with Part B Please. 5. Compare the values of Keq for each of the five solutions: a. Are any of the values outside the sample standard deviation for the set? b. Does the value of the equilibrium constant change when the concentration of either the reactants or products is altered? Why or why not? Explain this based on your calculations of Keq: c. What caused variation (three reasons) in your values of Keq? NOTE: the standard deviation is 3.9x102 The procedure is in the images Data: Unknown solution Equilibrium concentration of {FeNCS2+} in unknown solution(M) Equilibrium concentration [Fe3+](M) Equilibrium concentration [SCN-](M) Keq 1 3.7x10-5 9.6x10-4 1.6x10-4 2.4x102 2 6.2x10-5 9.4x10-4 3.4x10-4 1.9x102 3 1.1x10-4 8.9x10-4 4.9x10-4 2.5x102 4 1.1x10-4 8.9x10-4 6.9x10-4 1.8x102 5 1.8x10-4 8.2x10-4 8.2x10-4 2.7x102
A standard serum sample containing 102 meq/L chloride was analyzed by coulometric titration with silver ion. Duplicate results of 101 and 98 meq/L were obtained. (a) Calculate the mean error (b) Calculate the relative error (c) Calculate the relative accuracy