Analytical chemistry Definition and 25 Threads

  1. D

    SO2 Conversion Equilibrium Curve

    Hi... i want to draw Equilibrium curve for SO2 oxidation to SO3, i found following relations but don't know to use them... kindly tell me how to draw Equilibrium curve using these equations or any source on web from where i can get directly SO2 oxidation data Vs Temp? Equations are following...
  2. kofffie

    Chemistry Help with Complex Acid-Base Titration

    Help! I am confused with my assignment. it was about complex acid base titration. the analyte was citric acid and the titrant was a base. To find it, I need to search for C1V1=C2V2, however during the balanced equation, there is 3 mol of my base that will be reacting to 1 acid. Will the ratio of...
  3. phy_optics

    Halogen Lamp Spectrum 12V, 50W MR16: A vs B

    12V, 50W, MR16 halogen lamp spectrum is measured as shown ('B') with our newly developed mini-spectrometer having resolution ~1nm. But in internet it was similar to 'A' (We don't know how much resolution spectrometer they've used). Could anybody let me know what exactly the spectrum look like...
  4. T

    Analytical Chemistry Concentration Calc Question

    A lab mate and I are discussing how to properly interpret LCMS results and coming to different conclusions. We are taking a solid food sample and extracting it with 50:50 acetonitrile/water to determine the concentration of melamine in the food sample. Standard solutions were made that range...
  5. cliffordlim

    How Do You Calculate Equilibrium Concentrations in a Redox Reaction?

    Homework Statement Fe2+and Cr2O72- react as follows: 6Fe2+ + Cr2O7 2− + 14H + >>> 6Fe3+ + 2Cr3+ + 7H2O. The equilibrium constant for the reaction is 1×10^57. Calculate the equilibrium concentrations of the iron and chromium species if 10 mL each of 0.02M K2Cr2O7 in 1.14M HCl and 0.12M FeSO4...
  6. M

    Standard addition concentration positive

    I am computing limit of detection of zinc of an electrolyte. Using standard additions method, I have obtained positive x intercepts for 6/8 samples all very close to zero. Positive x-intercepts imply final concentration values to be negative. if x-intercept taken to be zero, the concentration...
  7. R

    Systematic treatment of equilibrium

    Homework Statement Determine [Zn2+], [CN–], and [HCN] in a saturated solution of Zn(CN)2 with a fixed pH of 1.060. The Ksp for Zn(CN)2 is 3.0 × 10–16. The Ka for HCN is 6.2 × 10–10. Homework Equations The Attempt at a Solution I don't have a phone or camera right now to take a picture of my...
  8. A

    Analytical Problem with Coulomb's Law

    Homework Statement Consider a parallel universe where the laws of nature as we know them are different, and aqueous solutions can have an excess charge. Two beakers are separated 1.20 meters and each contains 0.300 L of an aqueous solution of 6.40 × 10-6 M excess charge. One beaker has a net...
  9. A

    Find the Molarity of a Solution Using Concentrated Ammonia (28% by Mass)

    Homework Statement Calculate the molarity of a solution made by adding 35.5 mL of concentrated ammonia (28.0 % by mass, density 0.880 g/mL) to some water in a volumetric flask, then adding water to the mark to make exactly 250 mL of solution. (It is important to add concentrated acid or base...
  10. B

    Which Root Is Correct in Analytical Chemistry Equilibria?

    If a polynomial equation is solved for multiple roots in a system of equilibria (e.g. calculating extent of a reaction, or solving for [H+] in a complicated acid-base system, to give two basic examples) how do we know which, among the roots, is the correct solution (e.g. the correct extent or...
  11. W

    Analytical Chemistry: Calculate the pH.

    Homework Statement Calculate the pH of 5.0 x 10^-8 M HCLO4. What fraction of the total H+ in this solution is derived from dissociation of water? Homework Equations The Attempt at a Solution The only thing I know to do is take -log(5.0 x 10^-8) .
  12. A

    Analytical Chemistry - Systematic Treatment of Equilibrum

    Homework Statement Calculate the molar solubility of Ag2C2O4 (silver oxalate) in a solution that has a fixed H3O+ concentration of 1.0 x 10^-6 M. Homework Equations The Attempt at a Solution I found the pertinent reactions, the charge balance and the mass balance so far, but I...
  13. H

    Analytical Chemistry- Ksp problem help

    Homework Statement Find the concentration of Pb2+ in 0.0010 M KI with PbI2. Include activity coefficients in your solubility-product expression. The Ksp of PbI2 is 9.8*10^-9 Homework Equations Ksp= [Pb2+]\gammaPb2+[I-]2\gamma2I- Assume that [I-]=0.0010 M. The ionic strength of 0.0010 M Ki...
  14. W

    Analytical Chemistry UF: Comparing Wavelengths & Frequencies

    Question 20 from our final I just took (Analytical Chemistry UF). "You may recall that the wavelength of the sodium D1 line in vacuum is 589.7558nm. In air it becomes 589.5924nm. What is the difference in frequency for these two wavelengths." I said 0. All the other people did the...
  15. Z

    Analytical Chemistry HW: Ca2+ (mg) Estimation w/ 95% Confidence Level

    Homework Statement CaCO3 acts as an antacid for temporary relief of heartburn/acid-reflux. Free calcium ions in solution can be analyzed gravimetrically after acid digestion and precipitation with oxalate in basic solution to form an insoluble calcium oxalate monohydrate salt that can be...
  16. T

    How to Adjust KNO3 Solution Preparation for Temperature Variations?

    Homework Statement you want to prepare 500 ml of 1 M KNO3 at 20 C, but your lab and water are 24 C. How many grams of solid KNO3 (density= 2.109 g/ml) should be dissolved in a volume of 500 ml at 24 C so that the concentration will be 1 M at 20 C? what apparent mass of KNO3 weighed in air is...
  17. R

    Physical and analytical chemistry

    Homework Statement at 20 degree celcius, the solubility of a solid substance x in water is 42g/L. There are 3 solutions containing x kept at this temperature: S1 contains 5.1g/L,S2 contains 39g/L, and S3 contains 57g/L.so, how to make a saturated solution containing 45g x per litre overall for...
  18. R

    Physical and analytical chemistry

    at 20 degree celcius, the solubility of a solid substance x in water is 42g/L. There are 3 solutions containing x kept at this temperature: S1 5.1g/L, S2 contains 39g/L, and S3 contains 57g/L. if we want to make S1 saturated with x, is it possible that we can add an equal volume of S2 and S1...
  19. R

    Physical and analytical chemistry

    Homework Statement A rigid container,maintained at 50 degree celcius, is evacuated by a vacuum pump. After this, some liquid n-propanol is introduced into the container. part of the liquid will flash off inside the vacuum,but eventually the system will settle into equilibrium. what is the...
  20. T

    Analytical Chemistry: Preparing for Labs & Grades

    I am currently taking an Analytical Chemistry class which has labs in it. I did my first one last week and it wasn't so bad - I still have one more week to finish up my lab write up. This week though we are doing another lab, and my hopes are that I can prepare myself better for this week. I...
  21. M

    How Can You Identify Incorrectly Prepared Standards in AA Analysis?

    This is the problem: You are doing a typical AA ( atomic absorption spectroscopy analysis) What you don't know is that the standard calibration curve is incorrect you have made your concentration twice as concentrated. For exable you believe that you have 2,4,6,8 ppm but actualy you have...
  22. B

    Analytical Chemistry, Introductory

    It may seem that I will be taking an analytical chemistry course for my major in Biotechnology, and I have never really taken an analytical chemistry course. I have probably studied the topics in regular chemistry courses but I am unaware as to what exactly this course teaches or the topic(s) it...
  23. L

    How to Excel Analytical Chemistry

    I just got my Analytical Chemistry test grade. It's fine but not a great grade. Everybody thinks it was a problem of time constraint.I think it's because were given question types that are different from what is in our book. Around 70% is very acceptable. The rest is a complicated problem that...
  24. L

    What are some good books/websites for Analytical Chemistry?

    I am taking a 1 semester analytical chemistry course with a tough teacher (according to her students), and I want to have the maximum preparation for this course through all the means available. PS: I am a biology student. Thanks.
  25. J

    Analytical Chemistry involving buffer

    Homework Statement What volume of 0.200M HCl must be added to 250.0ml of 0.300M sodium mandelate to produce a buffer solution with a pH of 3.37? Homework Equations The Attempt at a Solution For 2 and 3, can I use the equation pH = pKa + log [A-/HA]? but for HCl isn't that 100%...
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