When a Levy-Jennings graph for TSH was checked, the mean of results was found to have shifted by +1.5 SD over the four days since the last check. All other assays were found to be performing as expected. On investigation, it was discovered that the batch of reagent had been changed. A phone call to the manufacturer revealed that there were no other reports of problems

When a Levy-Jennings graph for TSH was checked, the mean of results was found to have shifted by +1.5 SD over the four days since the last check. All other assays were found to be performing as expected. On investigation, it was discovered that the batch of reagent had been changed. A phone call to the manufacturer revealed that there were no other reports of problems

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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To calculate the unknown concentration of a chemical in a solid sample, 4 different calibrationcurves were plot using 4 different methods. Which of the following method is considered asacceptable? a. Method 4, R? = 0.998b. Method 1, R2 = 0.650c. Method 2. R' = 0.890d. Method 3, R' = 0.169
Below are responses generated using the isolated guinea-pig ileum preparation to determine a pA2 value for the cholinergic antagonist homatropine.Responses are expressed in millimetres +/- SDM (n = 4).Plot the data and then determine by Schild analysis the pA2 value and Schild slope. show calculationsWhat conclusions can you draw; does the experiment/data fulfil the criteria for a valid Schild analysis?
(i) An unknown sample (0.100 g dissolved in 100 mL ethanol) was then analysed by GC, among a number of otherpeaks, there was one at 9.5 min with integration 1250. Discuss how this could be quickly confirmed as being due to A. (ii) An aliquot (1 mL) of a solution of B (0.100 g dissolved in 100 mL ethanol) was added to the unknown sample. Now in addition to the peak at 9.5 min (integration 1250) there was a peak at 11.5 (integration 1000). Determine how much A was in the unknown sample.
Below are responses generated using the isolated guinea-pig ileum preparation to determine a pA₂ value for the cholinergic antagonist homatropine. Responses are expressed in millimetres +/- SDM (n = 4). Plot the data and then determine by Schild analysis the pA₂ value and Schild slope. So that's TWO drawn graphs to plot on LIN/LOG paper and submit..not EXCEL graphs please. What conclusions can you draw; does the experiment/data fulfil the criteria for a valid Schild analysis? Acetylcholine ACH Alone Concentration ACH + ACH + ACH + Homatropine Homatropine Homatropine 3 x 10-⁹M 1 x 10-M 3 x 10-M [Molar] 3 x 109 3 +/- 1 6 x 109 8 +/- 3 No response 3 x 10-8 28 +/- 6 10 +/- 4 No response 6 x 108 38 +/-8 21 +/-9 5+/-2 No response 3 x 10-7 55 +/- 5 43 +/- 7 27 +/-9 10 +/- 4 6 x 10-7 56 +/- 5 52 +/- 3 38 +/- 7 20 +/-7 3 x 10-6 55 +/-4 53 +/- 6 43 +/- 6 6 x 106 56 +/-2 54 +/- 5
Acetaminophen or paracetamol, the active ingredient in many pain killers absorbs in the UV range with a λmax at 250 nm in neutral solutions (methanol usually). Its extinction coefficient is 14 mM-1cm-1. Each commercially available tablet (Tylenol, Panadol or Herron) contains 500 mg paracetamol. Its molecular weight is 151.1. Using this information, calculate the dilution required to analyse the concentration of paracetamol in a commercially available paracetamol tablet. Start by dissolving the tablet in 100 mL methanol. Show working out.
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Below are responses generated using the isolated guinea-pig ileum preparation to determine a pA2 value for the cholinergic antagonist homatropine.Responses are expressed in millimetres +/- SDM (n = 4).Plot two data graph and then determine by Schild analysis the pA2 value and Schild slope. show calculationsWhat conclusions can you draw; does the experiment/data fulfil the criteria for a valid Schild analysis?
it has been noticed that adulteration of palmoil with carcinogenic dyes is on high.use the knowledge of analytical process to outline protocols you will follow to determine the quantitative and qualitative amount of the toxic dye spectroscopically.
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3. Seven analyses for the phosphorus content of a fertilizer resulted in 16.2, 17.5, 15.4, 15.9, 16.8, 16.3, and 17.1%. Find (a) the standard deviation, s, , and (b) the 95% confidence interval for the true value, H. 4. The following five values were obtained for the wt % of an organic acid in a sample: 30.3, 31.1, 32.6, 36.7, 28.9. Determine if the value of 36.7 may be rejected at the 90% (two-tailed) confidence level. 5. The concentration of a NaOH solution is determined in a single experiment by titrating a weighed sample of pure, dried KHP (MW = 204.229) with the NaOH. The data are: Weight of KHP = (11.6723 + 0.0001) - (10.8364 ±0.0001) g Volume NaOH = (32.68 + 0.02) - (1.24 + 0.02) mL Where the standard deviations are o, values. (a) What is the molarity of the NaOH? (b) Based on the propagation-of-error formula, what is the standard deviation of the molarity,oM ?
h) i) j) Ph + НО OSI(CH3)3 Br PPH3 1) "BuLi /THF/rt / 1.5 h H CH3 homo /rt / 1 h 2) -Si(CH3)3 OCH3 TiCl4 CH₂Cl₂/-78°C / 15 min PPh3/1₂ (1 eq) imidazole / THE 0°C-it
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