Q2(b). Resolution, plate number, plate height and a longer column
Compounds X and Y are separated by passing through a suitable chromatographic column of 30 cm length. Un-retained species passes through the column in 1.5 minutes. Data: X, retention time 14.5 minutes, peak width at the base 1.2 minutes; Y, retention time 15.2 minutes, peak width at the base 1.3 minutes. Use the data to determine the: (i) column resolution; (ii) average number of theoretical plates in the column; (iii) plate height; (iv) length of a new column to achieve a column resolution of 1.0; (v) time required to elute the slowest moving compound through the new column.
Model answer
The free solution for 2022 answers questions 1, 4, 5, 6, 7 and 10, the ones picked in its time plan. Question 2 is answered in full in the Geo-Scientist Chemistry Paper III, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
- All ten questions of each paper, with the question printed above its answer
- Instruments drawn as labelled diagrams, numericals worked with units
- Topic-wise weightage and a topic-wise index
Coverscolumn resolutiontheoretical platesplate heightchromatographyretention time
All parts of Question 2
- 2(a) Chromium and manganese in steel by spectrophotometry15 marks
- 2(b) Resolution, plate number, plate height and a longer column10 marks
- 2(c) Slit width that resolves the sodium D lines5 marks