Chemistry

answer

watching

184

views

periwinklejackal67Lv1

28 Sep 2019

i did '' determination of riboflavin in a vitamin supplement tablet using fluorescence spectroscopy'' Now i am writing up the lab , its formal lab report. need help with the introduction section of the lab report.

answer

watching

184

views

For unlimited access to Homework Help, a Homework+ subscription is required.

You have 0 free answers left.
Get unlimited access to 3.8 million step-by-step answers.

Get unlimited access

Already have an account? Log in

Keith LeannonLv2

28 Sep 2019

Unlock all answers

Get 1 free homework help answer.

Already have an account? Log in

Join us on Discord

Chemistry Study Group

Join now

Related questions

I am writing a lab report over the the spectroscopic determination of an acid/base indicator's pKa value.

I need help with the following quesions......

1. What factors could contribute to the inability of an analyst to obtain an isobestic point.

2. If the molar absorptivities of HInd- and Ind2- were determined at the isobestic point, how would they compare?

I need help with question 2

Lab 5. Determination of iron in a supplement tablet by atomic Prelab Helpful Reading: Discussion of atomic absorption spectrometry: The introduction to Chapter 21, section 21-1 and the part describing flames at the beginning of section 21-2 In this lab a flame atomic absorption spectrometer will be used to determine the amount of Fe in a vitamin pill. You may select your sample from one of the pills containing -9 mg/pil, Women's spectrometer detects following three types of pills: Energy Vitamin s Vitamin pills containing 18 mg/pill. The atomic absorption Fe well when the Fe concentration is between 1.25ppm and 5ppm Answer the following prelab questions: 1. A. How will you prepare your calibration solutions? You will use five calibration solutions in this lab, including the blank. A stock iron solution for atomic absorption spectroscopy will be made available to you that has a concentration of 1000 ppm (w/v) Fe. For an iron analysis the Varian atomic absorption spectrometer in the quant lab-requires samples with concentrations between 1.25 and 5 ppm (w/v) and a blank. You will prepare 5 calibration solutions, having respectively, the following final concentrations of Fe: 0, 1.25, 2.5, 3.5 and 5 ppm (w/v) Fe. These solutions will be prepared by diluting an appropriate number of microliters of 1000ppm (w/v) Fe with DI water in a 100 ml volumetric flask. Calculate how many microliters of stock iron solution are needed to prepare calibration solutions at the concentrations mentioned above. 2. How will you prepare your sample for analysis? Draw up one experimental plan for diluting your chosen pill to an appropriate concentration for the atomic absorption instrument using a micropipette. Specifically a. Which pill, from the two types mentioned above do you propose to analyze? How many mg of Fe is the pill expected to have? Assume that you will digest a vitamin pill as you did last week, and will dilute the digest to 100ml-this solution will be called vitamin solution 1 (VS1). You willuse a micropipette to transfer some liquid from VS1 to another 100mL volumetric flask and b. will ilute this to the mark. This second solution, vitamin solution 2 (VS2) will be the sample that you measure. What volume should be transferred from sample solution 1 to sample solution 2 with the micropipette? Draw a picture to illustrate your dilution scheme. Write out a sample preparation equation relating the estimated concentration in the mg/pll (based on the label) to the estimated concentration (in units of ppm) of Fe in the sample that will be measured. Do this in your lab notebook. c. d. Lab 5 Determination of iron/atomic absorption spectroscopy 31

I really need help with my Instrumentation lab report please.

Thank you

CHML 421 Chemical Instrumentation Lab Experiment 4 (Part 2 of Exp 3) Determination of Fluorescein in Antifreeze by Fluorescence Spectroscopy Fluorescence spectroscopy may be used as both a qualitative and quantitative analytical tool The observable excitation and emission spectra are characteristic of a given molecule and may be used to identify the fluorescing molecule. Emission spectra may also be used to quantitatively analyze fluorescent species. The intensity of radiated emission, keeping excitation and emission wavelengths constant, is proportional to the number of molecules in the excited state relaxing back to the ground state. This in turn is proportional to concentration of molecules in solution Where lfis the intensity of the emission radiation k is a proportionality constant for that particular cell and fluorescing species c is the concentration of the analyte in solution. Low concentrations of fluorescein yield intense fluorescence, thus concentrations in this lab are extremely low. In this experiment you will become familiar with the general use of fluorescence spectroscopy and determine the concentration of antifreeze. Chemical Hazards Fluorescein solutions are in 0.1 M NaOH, so use gloves and safety eyewear to avoid contact Laboratory Procedures Preparation of Calibration Standards 1. Prepare a 1 mg/mL (1000 ppm) fluorescein stock solution (50 mL) by dissolving 50 mg fluorescein disodium salt (MW 376 g/mol) in 0.1 M NaOH. (fnecessary prepare a second 100 ppm luorescein stock solution (50 ml) from 1000 ppm stock to prepare calibration standards.) 2. Prepare a set of 5 solutions (10 mL each) varying in concentration 02.0.5. 1.2, and 5 ppm fluorescein standard solution from 100 ppm stock solution of uorescein in 0.05 MINaOH Constructing Calibration Curves 1. Using the 2 ppm fluorescein solution obtain the excitation spectrum of fluorescein from 300 - 700 nm (select between 600 to 630 nm as emission wavelength). 2. Print out the spectrum 3. Using the same solution, obtain the emission spectrum of fluorescein from 300-700nm (select 325 nm as excitation wavelength).

Weekly leaderboard

Home

Homework Help 3,900,000

Chemistry 830,000

i did '' determination of riboflavin in a vitamin supplement tablet using fluorescence spectroscopy'' Now i am writing up the lab , its formal lab report. need help with the introduction section of the lab report.

Unlock all answers

Related textbook solutions

Basic Chemistry

Principles of Chemistry Molecular Approach

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related questions

Weekly leaderboard