analysis

  1. P

    Best method for the analysis of vitamins and metals in health supplements?

    I am looking at analysing a range of vitamin supplements in order to quantify both their water soluble vitamin and metal content. I intend to use LC-MS for the vitamins and FAAS for the metals. Are these the best methods would you say or is there a better method? Also I am not 100% sure on the...
  2. N

    Analyzing astaxanthin content with spectrophotometer

    Hi chem wizards! I'm not a chemist, only had a few basic chem classes in college. But I happen to have some H. pluvialis powder here that I need to analyze for cheap and I can get a cheap spectrophotometer on ebay, so I've been looking at articles to try to figure out what wavelength to look...
  3. JayneDoe

    Preparing a Gross Sample for Laboratory Analysis

    A carload of Hg-ore containing grains of cinnabar (86% Hg by mass; density= 8.19 g/cm3) and grains of basalt (containing no Hg; density=2.84 g/cm3) is to be sampled and analyzed for mercury. The average density of the bulk material is found to be 3.03 g/cm3. To keep the sampling error below...
  4. JayneDoe

    Analysis of a Nickel(II) Complex -Please for the love of God, someone please help me!

    A solid sample of a complex salt, with ideal composition Ni(NH3)6(NO3)2, was analyzed for nickel by dissolution in slightly acidic solution and precipitation as the dimethylglyoximate, Ni(DMG)2. 1. A sintered glass crucible of mass 12.7867 g was used to filter off the precipitate. The dried...
  5. K

    Dimensional Analysis Help

    Hello! I am struggling with setting up this dimensional analysis problem: "A particular MP3 encoder can convert 75 kilobytes of music per second from a typical music CD. How many minutes will it take to convert 12.8 megabytes of music from a CD?" I started with 75 kbytes per...
  6. K

    Wax ester GC analysis problem

    Hello to everyone, I currently working on enzymatic wax ester synthesis. The problem I am facing is that wax ester standards, purchased from a very famous company, do not appear in GC. However, samples were analyzed with the same method in GC and seem to have wax esters (I take the same GC...
  7. F

    More Grav. Analysis & Mole Calculations

    Q1: Kyotorphin (mole mass = 337.4 g/mol) is a small molecule, which has a role in pain regulation. A sample of cerebrospinal fluid taken from a patient has a kyrotorphin concentration of 280 ng/L. Find the number of kyrotorphin molecules in one millilitre of cerebrospinal fluid. n = CV = (2.8 x...
  8. F

    Gravimetric Analysis and Mole Calculations

    Q1: The amount of nickel in a sample of steel was determined by the following method. 3.18 g of the steel was dissolved in a mixture of hydrochloric and nitric acids. This converted all of the nickel into Ni{2+} ions. The solution was neutralised with dilute ammonia and a solution of...
  9. N

    HELP! Design an experiment using sequential qualitative analysis to determine whether

    I need help with the following chemistry question! Please help! Design an experiment using sequential qualitative analysis to determine whether a solution contains acetate or carbonate ions. For each stage of the test, write net ionic equations for the reaction that produces the precipitate.
  10. T

    Dimensional Analysis #1

    Hello, If a woman has a mass of 115 lb, what is her mass? I solved it by saying: Mass in grams = (115 lb) (453.6/1lb) = 5.22 x10^4 --------I believe I solved it, this post can be ignored. :)
  11. C

    Retrosynthetic Analysis Help!

    Please help me with retrosynthetic analysis. I have tried to solve different ways, but get stuck halfway through. Here is a link to the molecules. THANK YOU! Here are the assignment directions. Please choose one molecule from the list of four molecules below and devise a retrosynthetic...
  12. C

    aspirin analysis please help?

    I need help with te last three problems. i dont need answers but the explination of how to th problems For problem D i tried this 0.1327/0.249/0.686 and got 0.7769 and it was marked wrong. I Also tried 291mg/100ml= 2.917mg/ml times 2.23ml/100ml=0.0650 and i also got that wrong. please help:(...
  13. A

    dimension analysis question

    completely stuck i keep getting the wrong answer. Automobile batteries contain sulfuric acid, which is commonly referred to as battery acid. calculate the number of grams of sulfuric acid in 1.00 gallon of battery acid if the solution has a density of 1.29 g/mL and is 38.7% sulfuric acid by...
  14. P

    analysis

    Greetings, can anybody help me undertand the following questions please. How do we identify chromophores of our molecule if there is any which are fluorescent ? How can we identify the major IR absorption regions of the molecule according to its functional group? The drug that I deal with...
  15. P

    XRD ANALYSIS help

    I've just ran XRD analysis of Fe (fine powder), FeCl3.6H20. I am using Xpert Highscore software. I am unsure what some of the collumns means in the pattern list - Score? Displ.[°2Th]? Scale Factor? Just an understanding of what they mean would be, I need to prove that they are the compounds...
  16. S

    Chemistry- Analysis of a Hydrate

    A hydrate of Ni(NO3)2 is to be analyzed. A sample of the hydrate is weighed in a clean, dry and covered crucible. The mass of the crucible and sample is 34.5624 g. When empty, the crucible and cover are heated to a constant weight of 31.2016 g. The crucible with sample is heated (to drive...
  17. A

    I need help with dimensional analysis!

    How do I convert 856 mg to kilograms using dimensional analysis? i'm so confused and I really need help!:(
  18. K

    Unit Comversion/Dimensional Analysis Question:

    Hello! I am returning to college for a second B.S. after graduating college over a decade ago, and now I'm taking an inorganic chem prerequisite. I know this is a very basic problem, but I think I'm not clearly understanding either a sig fig or rounding rule here. I must state that I didn't...
  19. F

    Sequential Qualitative Analysis HELP!!

    I'm taking an online course so I have no help when things are unclear. And things are UNCLEAR. I don't understand how you create sequential qualitative analysis flow chart firstly. Could someone please give a detailed description of how you create one. Specifically how you come up with a...
  20. R

    Elemental analysis of functionalised silica

    Hi all I've made some functionalised silica in the lab according to a method laid out in a PhD thesis and just got the elemental analysis results back. The structure is; [silica bead]-Si-O-Si(CH3)(CH3)CH2-CH2-CH2-NH2 The PhD the method came from said he calculated the values should be C =...