What is the role of ammonium hydroxide (NH4OH) in the experiment that deals with the determination of calcium and phosphorous in soil?

EHS 243

Instrumental Analysis

Exam I

May 3, 2019

Hard Copy of Your Exam is DUE on Monday 5/6/19 @ 1:10 pm

(Please be specific in your answers)

Name ________________________ 1. You are collecting samples for analysis; name the typical information you must record in your sampling

logbook? (2 pts)

2. In the determination of Pb in a soil sample, why did you use the following two solutions: 6 M solution of CH3COOH and 0.25 M solution of K2CrO4? (2 pts)

3. You are planning to test two different samples (liquid and solid) for lead contamination. How do you test these two samples? (2 pts)

4. What is the role of ammonium hydroxide (NH4OH) in the experiment that deals with the determination of calcium and phosphorous in soil? (1 pt)

5. Can you use NaOH in lieu of NH4OH in the experiment that deals with the determination of Ca and P? (2 pts)

6. You need to run your sample thru IR; but the sample seems to be a corrosive compound! What do you do and WHY? (2pts)

7. Name the benefits and limitation of the distillation process. (2 pts)

8. Name the differences between distillation, extraction, and filtration (3 pts)

9. Name the criteria that are necessary for a compound to be IR active. (2 pts)

10. How does an IR work? (2 pts)

11. Whenever you are working with an AA, what do you have to do to get the best possible result and WHY? (2 pts)

12. Name different components of an AA. (2 pts)

13. What is/are the difference/s between AA, and IR? (3 pts)

14. You took 2 mL out of 2 L of a stock solution containing Pb and raised its volume to 100 mL. Then you injected 1 mL out of this diluted solution into an AA. The resulting concentration of Pb for this solution was

50ppm. Find the actual concentration of Pb in the original solution. (3 pts)

15. Name the limitation/s of AA, ICP and IR. (3 pts)

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