posted by .

Physical Developer (PD) is a set of solutions used to develop latent fingerprints on different porous and nonporous surfaces. It is often used to develop fingerprints on currency. Below are FBI recipes for PD. Solution 1 serves as a cleaning solution before using a mixture of solutions 2 and 4 in which the fingerprint is developed due to a redox reaction causing the deposition of metallic silver within the ridges of the fingerprint. Determine the concentration of each ingredient in the four solutions. The final volume for each solution is 1.00 L.

Solution 1: 25.0 g of maleic acid (C4H4O4)
Solution 2: 30.0 g of iron(II) nitrate [ Fe(NO3)2 ]
80.0 g of iron(II) ammonium sulfate [ Fe(NH4)2(SO4)2 ]
20.0 g of citric acid (C6H8O7)
Solution 3: 3.00 g of N-dodecylamine acetate (C14H31NO2)
4.00 g of synperonic-N (skip-this is a mixture)
Solution 4: 200.0 g of silver nitrate

I don't really know where to start in terms of calculations that would help in solving this problem. I can deduce that the metallic silver deposition in the ridges of the fingerprint would obviously contain Ag and an anion from one of the solutions (maybe solution 2). Thanks in advance for any help.

  • Chemistry -

    This is a very simple problem. I suspect you are getting trapped from all of the stuff that goes on before the question. Forget everything in the problem except the last two sentences; ie., Determine the concn of each ingredient AND the final volume in each is 1 L. All the rest is just to overwhelm you with information that is of no use..
    All are worked alike. Here is what you do.
    Step 1. mols of ech ingredient = grams/molar mass = ?
    Step 2. M = molarity = mols from step 1/1 L = ?

  • Chemistry -

    I also want to point out that the problem DOES NOT say what units are to be used for the concentration. i chose to do them by M because I'm sure that's what the author of the problem meant; however, note that for solution 1 you could have said that (maleic acid) = 25,0 g/L and that would be right. The others could be done similarily, also.

Respond to this Question

First Name

School Subject

Your Answer

Similar Questions

  1. science

    i am doing a science project comparing human and animal fingerprints. I can't seem to find out if cats and dogs have identifyiable fingerprints. does anyone know?
  2. Science

    We are doing a science fair and we are unsure of what our aim/investigation should be. However we know we want to do something with fingerprints. What can we do?
  3. Advanced Biology

    How can muscle protein fingerprints be used to study evolutionary relationships among organisms?
  4. English Comma splices and run on sentences

    Janet left fingerprints on the glass, the detectives were able to solve the crime. Janet left fingerprints on the glass so the detectives were able to solve the crime. Janet left fingerprints on the glass; consequently, the detectives …
  5. English

    Can you please check if these sentences are OK?
  6. chemistry

    would the measure absorbance id an FENCS+ ion solution be higher, lower, or unaffected if there were fingerprints on the cuvette?
  7. Superglue fuming--fingerprints

    What is an amino acid? Why do they cause superglue to stick to my fingerprints on a cd when I place the cd in a plastic box covered with plastic wrap?
  8. ICT (Programming)

    Based on the table below, Based on the table below, using a CASE structure to display the type of designation when a specific code is entered. CODE TYPE OF DESIGNATION L LECTURER S SENIOR LECTURER D DEAN A ADMINISTRATION (other code) …
  9. forensic

    Select the proper order of examination "Fingerprints, trace evidence, DNA" "Disease diagnosis, DNA, fingerprints" "Ink analysis, content analysis, DNA" "Handwriting, ink analysis, DNA" None of the above my answer is the first one
  10. Guidance and discipline

    If children do not develop a competence in fundamental skills of movement they may: A. Never develop fine motor skills B. Lose muscle tone C. Develop poor body image D. Be clumsy in physical actions. Is it C ?

More Similar Questions