Non-retained 3.1 -Name: _________________________________________Section #: ______________________________________CHEM 425: INSTRUMENTAL METHODS OF ANALYSISMID-TERM EXAM IXXX 140 PointsInstructor: XXXTotal PtsPossibleQuestion # GradeCalculations 40 pts1Multiple choice (5 pts each)60 pts1-12Short Answers (5 pts each)40 pts12345678EXAM GRADE 140-Honor Pledge: Copy the following and sign below.I pledge on my honor that I have not given or received any unauthorized assistance on this examination._________________________________________________________________________________________________________________________________________________________________________________ (Signature)Calculations (40 pts total)1. The following data apply to apply to a column for liquid chromatography:Length of column: 25.7 cmFlow rate: 0.313 mL/minVM: 1.37 mLVS: 0.164 mLA chromatogram of species A and B provided the following data:Retention Time, min Width of Peak Base (W), minNon-retained 3.1 -A 13.3 1.07B 14.1 1.16 Calculate:A)the number of plates and plate height from each peakB) the capacity factor for each peakC) the selectivity factorD)the resolution[Type text]E) the expected resolution, if the column length was doubledF) the expected capacity factors, if the column length was doubledG)the length of column necessary to give a resolution of 1.5H)the time required to separate A and B with a resolution of 1.5[Type text]Multiple Choice – 5 points each – right or wrong - no partial credit (Total 60 points) 1. How will increasing the column length by a factor of 4 affect resolution?A. No changeB. Increase by a factor of 4C. Increase by a factor of 2D. Decrease by a factor of 2E. Increase by 21/22. How will increasing column length by a factor of 4 affect separation time? A. No changeB. Increase by a factor of 4C. Increase by a factor of 2D. Increase by 21/2E. Decrease by a factor of 43. By what factor will resolution be improved when k’B (the capacity factor) is increased from 1 to 2?A. 2B. 1.5C. 4D. 1.33E. 1.754. By what factor will the resolution be improved when α (the selectivity factor) is increased from 1.5 to 2?A. 1.5 B. 1.33C. 2D. 1.75E. 3For questions 5-9, indicate which terms (i.e. A, B, C) in the van Deemter equation will be affected and how.5. A smaller particle size of the stationary phase packingA. Decrease A onlyB. Decrease C only C. Increase A but decrease CD. Decrease both A and CE. Increase B[Type text]6. A larger film thickness on the stationary phase packingA. Decrease B onlyB. Increase A onlyC. Increase C onlyD. Decrease C onlyE. Decrease both A and C7. A distribution of particle sizes in the stationary phase packingA. Decrease A onlyB. Increase A onlyC. Increase both A and CD. Decrease C but increase BE. Decrease A but increase C8. Small diffusion coefficient of the analyteA. Decrease B but increase CB. Increase C but decrease BC. Increase C onlyD. Increase B onlyE. Decrease A only9. Lower solvent viscosity (LC)A. Decrease B but increase CB. Increase C but decrease BC. Increase B but decrease CD. Increase B onlyE. Decrease C only10. How is H (plate height) affected by a very high linear flow velocity?A. Increased B. Decreased C. Unchanged11. How is H (plate height) affected by increasing the column length?A. Increased B. Decreased C. Unchanged12. How is k’ (capacity factor) affected by increasing the column length?A. Increased B. Decrease C. Unchanged[Type text]Short Answers – 5 points each (40 pts total)1. What carrier gas (mobile phase) do we employ for GC separations in the CHEM 425 lab?2. What other gases are employed in the GC (425 lab) and for what purpose?3. What stationary phase do we employ for LC separations in the CHEM 425 laboratory?4. How would you change the mobile phase to increase retention of analytes on the LC in the 425 lab? Should this increase or decrease resolution?5. What would you change to decrease the retention of analytes on the GC? Would this increase or decrease resolution?6. What two detectors are employed on the LC in the 425 lab?7. What two detectors are employed on the GC’s in the 425 lab?8. Why is smaller better for high efficiency separations (e.g., small particle sizes, small columndiameters (GC), thin stationary phase film thicknesses)? [Type text][Type