(a)
Interpretation:
The value standard deviation during the determination of carbon monoxide in automotive exhaust gas is 0.030ppm on the basis of extensive past experience. The 90% confidence interval for triplicate analysis is to be determined.
Concept introduction:
The formula that will be used-
Here,
N = degree of freedom
s = standard deviation
t = constant
(b)
Interpretation:
The value standard deviation during the determination of carbon monoxide in automotive exhaust gas is 0.030ppm on the basis of extensive past experience. The number of measurement is to be determined when 90% confidence interval is to be 0.50ppm.
Concept introduction:
The formula that will be used-
Here,
N = degree of freedom
s = standard deviation
t = constant
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Chapter A1 Solutions
Principles of Instrumental Analysis
- A volumetric calcium analysis on samples of the blood serum of a patient believed to be suffering from a hyperparathyroid condition produced the following data: mmol Ca/L = 3.10, 3.08, 3.28, 3.15, 3.26, 3.12, 3.14, 3.18, 3.25, 3.11, 2.95. Calculate: Mean Standard deviation Coefficient of variation What is the 95% confidence interval for the mean of the data, assuming no prior information about the precision of the analysis? Apply the Q test to the following data sets to determine whether the outlying result should be retained or rejected at the 95% confidence level. ( work on the first measurements according to your case)arrow_forward1. A student performed this experiment and obtained the following concentration values: 0.02813 M, 0.02802, and 0.02788 M a. what is the mean concentration? b. what is the standard deviation of these results? 3. how would the following errors affect the concentration of Cl- obtained in question 2b? give your reasoning in each case. a. the student read the molarity of AgNo3 as 0.02104M instead of 0.02014M b. the student was past the endpoint of titration when he took the final buret reading.arrow_forwardA method for the detection of morphine is used to generate a calibration curve in which the assay response (y) is plotted versus morphine concentration (x, in mg/L). This gives a straight line with a slope (m) of 0.241 and a y-intercept (b) of 0.011, where y = mx + b. The slope of this line has a standard deviation of ±0.007, and the standard deviation of the intercept is ±0.006. If the sample from an athlete gives a response of 0.506 ± 0.013 in this method, what is the concentration of morphine in the sample and estimated precision of this concentration?arrow_forward
- What are the advantages and disadvantages of using external standards in instrumental analysis?arrow_forwardDescribe the following as used in analytical chemistry a) semiqualitative analysis b)Assay c) derivatisationarrow_forwardAnalytical chemistry is a particular field within the broader spectrum of the chemical sciences, in which many times the focus of analytical experiments is to develop new methods to analyze compounds, either structurally or by determining concentrations of compounds. One of the processes analytical chemists use to determine the exact concentration of a working solution is called standardization. In your own words, describe the differences between a primary, secondary, and tertiary standard, and describe the underlying concept behind the standardization process. Why is it done?arrow_forward
- Was the gradual color change observed when the sodium thiosulfate (Na2S2O3) crystal was added to the aqueous solution of KI/12 in Station Cevidence of a chemical or physical change?arrow_forwardIn your own words, describe the following terms as used in analytical chemistry. a) semiqualitative analysis b) Assay c) derivatizationarrow_forwardA chemist obtained the following data for the percent compound Z in triplicates (n=3) of an insecticide preparation: 7.47, 6.98, and 7.27. Calculate the 90% confidence limit for the mean of the data assuming that only information about the precision of the method is the precision for the three data points.arrow_forward
- A volumetric calcium analysis on triplicate samples of the blood serum of a patient believed to be suffering from a hyperparathyroid condition produced the following data: mmol Ca/L = 3.55, 3.65, 3.14. What is the 95% confidence interval for the mean of the data, assuming(a) No prior information about the precision of the analysis?(b) s → σ = 0.056 mmol Ca/L?arrow_forwardFor EACH type of gravimetric analysis:Give actual applications of each analysis. Include the SPECIFIC methodology for each sample chosen.arrow_forwardAs part of an analytical chemistry laboratory course, a student measured the Ca2+ content in two water samples, city-supplied drinking water and well-supplied drinking water, using two different analytical methods, flame atomic absorption spectrometry (FAAS) and EDTA complexometric titration. The results of this experiment are given in the table as the mean Ca2+concentration (?¯) and standard deviation (?) in parts per million (ppm). Each sample was measured five times (n=5) by each method. Method City-Supplied Drinking Water (?¯±?x¯±s) Well-Supplied Drinking Water (?¯±?x¯±s) FAAS 57.57±0.68 ppm 64.77±0.70 ppm EDTA titration 58.32±0.96 ppm 65.62±0.97 ppm Method Comparison: For each drinking water sample (city and well), compare the Ca2+ content measured by FAAS and EDTA titration. Calculate the ? value for each sample. Do the methods produce statistically different results at the 95% confidence level when measuring the Ca2+content of the city-supplied drinking water? Do the…arrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning