25x – This granule of Tin measuring 0.004” and 99.95% purity and others like it were used to make the following micro-chems.

40x – The piece of Tin dissolving in 1 drop HNO3 & 1 drop H2O.

40x – Semi-opaque super-saturation crystals of the dissolved tin.
The air bubbles are the result of tiny fragments of Tin still dissolving.

10x – The tin is not completely dissolved in the HNO3 + H2O solution. And there are several other areas of tiny fragments of Tin that are still dissolving as noticed by the air bubbles.
When heat was applied to see if the tin would dissolve further the solution became this bluish white gelatinous solution.
The semi-clear spots are the remaining opaque crystals that have not gone into solution.

10x – The Sn + HNO3 + H2O solution forced to dryness by applying a cigarette lighter flame to underside of glass slide.
The bluish-white gelatinous center is a good indicator of Tin in this type of solution.

10x – Placed a drop of HNO3 on the dried area shown in previous image and gently heated, then a single crystal of potassium dichromate (K2Cr2O7) was inserted.
No precipitate formed as the K2Cr2O7 slowly dissolved.
K2Cr2O7 is not a useful reagent in this circumstance.

10x – The preceding image after it was thoroughly dried by gentle application of a Bic lighter flame.
The primary purpose of placing this image here is only to show why K2Cr2O7 is not a useful reagent in this circumstance. However, K2Cr2O7 might well be an ideal reagent if other elements were present.

30x – Another granule of tin is being dissolved in 1 drop of HNO3, but no water, which produces these white crystals. I do not know what the reason is for these crystals other than super-saturation. Nevertheless, this deposition of white crystals could be a significant clue for Tin.
By adding 3 drops of water these white crystals dissolved.

10x – A single crystal of KI was inserted into the preceding imaged solution (1 drop HNO3 and 3 drops of H2O).
There was an instant yellow color, but apparently the orange-red color is a KI reaction to the HNO3, which is further shown in next image.

10x – The KI reaction that began in the preceding image has now progressed to the point that orange crystals formed, but are also reacting with the HNO3 forming a brown color, which became black reduced Iodine crystals.
It is clear that 3 drops of water was insufficient dilution to avoid the KI reaction with the HNO3.

40x – Placed a Tin granule into a drop of concentrated HCl.
There was only a minor reaction, so heat was applied to aid in any possible digestion of the tin. Even with heat there is only a little dissolving action.
This image is of the dried HCl and whatever amount of tin was digested by the HCl.

20x – A single crystal of KI (potassium Iodide) was inserted into the preceding digestion after another drop of HCl was added and a little heat applied.
The KI did not cause a precipitant to form. However, when the solution came to nearly dry there was a definite reaction between the KI and dissolved tin by the orange and yellow colorations.
The bluish-green tints I suspect are not a function of the KI, but a reaction of tin in the acid as it concentrates due to drying.

40x – A magnified view of the preceding image as the solution is coming to dry, but is not completely dry. The solution can still be seen around the remaining un-dissolved piece of tin metal.
What I do find interesting is the white crystalline formations, which could be confused with Lead Chloride (PbCl).

Several other reagents are required to find which will allow positive identification of Tin in an acid solution.

Lead (Pb) was added to another series of microchems and the results are not worthy of posting.

20x – This toothpick tip was dipped in the original HNO3 acid that dissolved the Tin.
No metal is reduced.

40x – The toothpick in the preceding image was re-ignited and still no reduced metal.
In this particular circumstance the white area indicates a form of tin, but lots of metals, under similar circumstances produce this type of white residue.