CHEM 267L Experiment 3 LLE Design Template

Report Sheet: Characterization of a Weak Acid. UNKNOWN NUMBER 63 A. Standardization of NaOH Solution TRIAL [HCI] Volume Moles Moles Volume HCI [HOEN] 24.65 НОEN 0.0026 25.75 НОEN 0.10097 1 0.0026 0.1002 25.89 25.73 2. Average [NaOH]. B. Identification of the Unknown Acid Determination of Molecular Weight TRIAL [NaOH] Volume Moles Moles Grams Molecula Unknown Unknown r Weight (g/mol) НОBN НОEN 0.294 7 24.07 0.2943 2. Average Molecular Weight (g/mol)

19. What type of sample analysis usually operates on the 10-4 g scale of sample size? A. macro analysis C. micro analysis B. semi-micro D. ultra-micro analysis analysis 20. Under what classification does a constituent group when its concentration is between 100 ppm and 1ppb? A. Major constituents B. Interferences C. Minor D. Trace constituents constituent

Extraction of Caffeine Post-lab 1. What group of organic compounds does caffeine belong to? 2. Draw the structure of caffeine as a line formula. Redraw the structure of caffeine,showing all carbon and hydrogen atoms. 3. What is the molecular formula for caffeine? Use the molecular formula of caffeine tocalculate its molecular weight. 4. What does it mean for two solvents to be immiscible? 5. On the report sheet, you calculated your percent recovery of caffeine. a. If your percent was less than 90%, give at least one reason why it was less. b. A group of students have their percent yield more than 100%, give at least one reasonwhy it was more than 100%. Do NOT simply say “human error.” Be specific about the typesof errors (human or otherwise) that may have occurred, leading to a recovery more than eorequal to 100% (Is this possible Why?)   6. Based on what you observed during this experiment, is dichloromethane denser OR lessdense than water? Explain your reasoning. 7. Based on what…

Which of the following is incorrect: General steps in qualitative analysis include: Method selection, sampling, sample processing, calibration & measurement. b. Quantitative analytical methods include: gravimetric, volumetric, spectroscopic and electroanalytical methods. c. The first step in sample processing is sample preparation. d. Replication improves the quality of results and their reliability. e. In quantitative analysis there should be a direct proportionality between a measured property and the concentration or amount of substance. Please fill in the spa ces one of the following characters (a or b or e or d or e)

Redraw the flowchart

Need help determining the acidic component in an unknown sample.

M1= 25mL p

Trial 1: Initial pH= 3.92mL Mass of KHP and Paper= 0.868g Mass of paper= 0.357g Mass of KHP= 0.511g Trial 2: Initial pH= 4.09ml Mass of KHP and Paper= 0.870g Mass of paper= 0.359g Mass of KHP= 0.511g 1)Use Kb, the number of moles of C8H4O4^2- at the equivalence point, and the total volume at that point to calculate the pH for each sample at the equivalence point. Compare these calculated results with the experimental results.

How do I calculate this?

▪ In a blood alcohol analysis by GC-FID, methanol elutes at 1 min, ethanol at 2 min, IPA at 3 min, and IS at 4 min. In the patient sample, the analyte elutes t 2 min and the IS at 8 min. What is the relative retention time and the analyte in the patient? ▪ A) methanol B) Ethanol ▪ C) IPA

Understanding of food analysis methods.  Principles of method described compared to other techniques.   1 The MOHR Titration, AOAC Method? What is it and how does it work? How can it be used to quantify salt in a sample. 2 Are there any advantages and/or disadvantages of this method?3 Are there any alternate methods better than the Mohr Titration toquantitatively determine salt in a sample? 4. Diseases with recent statistics? Refer to World Health Organisation? 5. Why analayse salt? 6. Consumption? 7.  Main aims of study?