Revealing Fingerprints With Silver Nitrate

Revealing Fingerprints With Silver Nitrate

Another Method from the same chemistry book.

Weigh 0.3 grams of AgNO3.

And pour it into 10ml of distilled water.

I sprayed it and I shone it with an LED lamp (a UV lamp is better).

Now I got this:

I didn’t know why it was a line like that, but it worked.

I didn’t find any other fingerprints and the fingerprint that I have is hard to see.

Well, this experiment is considered as a fail. I rather use the iodine fuming method that I used the last time. The silver nitrate reacts to the salt on the fingerprint and produces silver chloride, just like on the skin.


13 Replies to “Revealing Fingerprints With Silver Nitrate”

  1. Ah yes a UV light would give quite a different image.
    And a surprising number of things have been discovered quite by accident, by people doing experiments and looking for something else! 🙂

  2. Robyn Haynes – Australia – Robyn enthusiastically pursues a green and writerly life on the north coast of New South Wales, Australia, where her background as a doctor of social anthropology equips her with an interesting slant on the human condition. She spends much time indulging a passion for her garden where she ponders life and attempts to stave off existential angst. In her more reflective moments she makes wry observations on courtyard gardening and its parallels with life.
    Robyn Haynes says:

    I really like the way you experiment to answer your enquiring mind Dan. Trial and error are the greatest teachers

  3. I think the problem is the lamp. I used a regular LED lamp, but UV lights are better. I can use sunlight but since it rainy everyday, no sunlight. And you’re right, trial and error. You just need to find the problem, fix it, and the experiment will work 🙂 Thanks for teaching me 😀 That’s why it’s “experiment”.

  4. Most experiments are trial and error. Sometimes they work, sometimes they don’t, but either way you learn something. 🙂
    Maybe silver nitrate works better with finger prints on glass or something. 🙂

  5. Interesting I wonder what the police use?

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