0 votes
38 views
in Analytical Chemistry by (450 points)
A chemistry student needs to analyze the composition of a soil sample using elemental analysis. The student has to determine the percentage of carbon, nitrogen, and sulfur present in the sample. How can the student perform elemental analysis and calculate the percentage of each element in the soil sample accurately?

1 Answer

0 votes
by (310 points)
To perform elemental analysis and determine the percentage of carbon, nitrogen, and sulfur in the soil sample, the student can follow these steps:1. Dry and homogenize the soil sample: Remove any debris, such as rocks or plant material, from the sample. Then, dry the soil in an oven at 105C for 24 hours to remove moisture. After drying, grind the soil to a fine powder using a mortar and pestle or a soil grinder to ensure a homogenous sample.2. Weigh the sample: Accurately weigh a known mass of the homogenized soil sample  e.g., 1 gram  using an analytical balance. Record the mass of the sample.3. Elemental analysis: There are several methods to perform elemental analysis, but one common method is the Dumas method, which uses a combustion analyzer. The analyzer combusts the sample at high temperatures in the presence of oxygen, converting the elements of interest  carbon, nitrogen, and sulfur  into their respective gaseous forms  CO2, N2, and SO2 . The gases are then separated and quantified using gas chromatography or infrared detection.4. Calculate the percentage of each element: The elemental analyzer will provide the mass of each element  carbon, nitrogen, and sulfur  in the sample. To calculate the percentage of each element, divide the mass of the element by the initial mass of the soil sample and multiply by 100.Percentage of element =  mass of element / mass of soil sample  x 100Repeat the analysis for at least two more subsamples to ensure accuracy and calculate the average percentage for each element.By following these steps, the student can accurately determine the percentage of carbon, nitrogen, and sulfur present in the soil sample.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...