A gas chromatogram of a mixture of toluene and ethyl (a) Measure w1/2 for each peak to the nearest 0.1 mm. When the thickness of the pen trace is significant relative to the length being measured, it is important to take the pen width into account. It is best to measure from the edge of one trace to the corresponding edge of the other trace, as shown at the bottom of the left column. (b) Find the number of theoretical plates and the plate height for each peak.

A gas chromatogram of a mixture of toluene and ethyl (a) Measure w1/2 for each peak to the nearest 0.1 mm. When the thickness of the pen trace is significant relative to the length being measured, it is important to take the pen width into account. It is best to measure from the edge of one trace to the corresponding edge of the other trace, as shown at the bottom of the left column. (b) Find the number of theoretical plates and the plate height for each peak.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter6: Random Errors In Chemical Analysis

Section: Chapter Questions

Problem 6.15QAP

See similar textbooks

Similar questions

Consider the peaks for heptane (14.56 min) and p-difluorobenzene (14.77 min) in the chromatogram. The column is 30.0 m long. (a) Measure w1/2 for each peak and calculate the number of plates and the plate height for each. (b) From w1/2, compute w for each peak and find the resolution between the two peaks.
The height of three peaks; A, B, and C obtained in a gas chromatogram are 20.6 mm, 17.5 mm and 40.6 mm. The width of the peaks, at half height, are 4.4 mm, 4.0 mm and 3.9 mm, respectively. Calculate the percentage composition of A in the sample.
TLC was used to compare the solubility of two compounds A and B in a solvent system (acetic acid, methanol, H2O). The distances that solvent has moved in the silica gel TLC was 12 cm. and for the compounds were 2 and 8 cm respectively. (a) Calculate the Rf values and which compound is more soluble and which one is more polar. (b) What are the factors affecting the Rf value
A young researcher set out to develop a method for quantifying the polycyclic aromatic hydrocarbon (PAH) content in a contaminated soil sample using open tubular gas chromatography. During the initial stages of method development, the researcher was unable to separate the early eluting compounds, anthracene and naphthalene, with baseline resolution. Select the possible modifications the researcher could make to improve the resolution. use a column with a smaller inner diameter decrease the column length increase the stationary phase thickness increase the temperature choose a different stationary phase
Barium sulfate from a 1.300-g sample was contaminated with 9.4 mg of Fe2(SO4)3 and weighed a total of 314.0 mg. Calculate a) the apparent percent BaSO4 (Apparent – the value of analyte concentration obtained when the interference is not considered) b) the true percent BaSO4
4.Consider the peaks for pentafluorobenzene and benzene in the gas chromatogram shown here. The elution time for unretained solute is 1.06 min. The open tubular column is 30.0 m in length and 0.530 mm in diameter, with a layer of stationary phase 3.0 μm thick on the inner wall. a) Measruing the width, w, at the baseline on the chromatogram, find the number of plates for these two compounds b) Use your answer to (a) to find the resolution between the two peaks c) Using the number of plates N=sqrtN1*N2 with the values from (a) calcuate what the resolution should be and compare your answer with the measured resolution in b
(5) An ion chromatograph is used for the determination of chloride ions. Seven replicate measurements of low level samples are performed and the results are: 20, 21, 18, 22, 20, 22, and 21 µg/L. What is the method detection limit for chloride?
You have obtained a gas chromatogram of a two component mixture of compounds A and B. The height of peak A is 3.84 cm. and the width at half height is 1 cm. The height of peak B is 3.49 cm. and the width at half height is 1.36 cm. The percentage of a component in the mixture is proportional to peak area. Estimate peak areas by multiplying height by width at half height. What was the percentage of compound B in the mixture? (Enter your answer as a number without any percent symbol or the word percent.)
How can you use ion exchange Chromatography to de-ionize water? Please shortly write at your own words. (4-5 lines maximum ).
How can you use ion exchange Chromatography to de-ionize water? Please shortly answer at your own words. Answer should be to the point (specific 4-5 lines).
3c. A solution containing 2.50 mM X (analyte) and 1.20 mM S (standard) gave peak areas of 2509 and 7132 respectively, in a chromatographic analysis. Then, 1.00 mL of 6.00 mM S was added to 5.00 mL of unknown X and the mixture was diluted to 10.0 mL. This solution gave peak areas of 4016 and 3138 for X and S, respectively. Calculate i. the response factor for the analyte ii. the concentration of S (mM) in the 10.0 mL of mixed solutioniii. the concentration of X (mM) in the 10.0 mL of mixed solutioniv. the concentration of X in the original unknown solution
(6) Ms. Muna Al Naabi in the Analytical chemistry laboratory wanted to separate chlorophenol by liquid chromatography using C-18 column with 10 cm long. She has observed that a chromatogram with compound elute in 9.0 min with W½ = 2.0 min. Find the number of theoretical plate and plate height (in mm).