Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN 3 videos
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| Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN 3 videos |
an experiment NH4Cr2O7 + HgSCN ignited by fire the result was a kind of tentacle comming out of it,
The volcano demonstration involves igniting a pile of the salt, which initiates the following exothermic conversion:
(NH4)2Cr2O7(s) → Cr2O3(s) + N2(g) + 4H2O(g) (ΔH = −429.1 ± 3 kcal/mol)
Like
the well-known explosive ammonium nitrate, it is thermodynamically
unstable. Its decomposition reaction proceeds to completion once
initiated, producing voluminous dark green powdered chromium(III) oxide.
Not all of the ammonium dichromate decomposes in this reaction. When
the green powder is brought into water a yellow/orange solution is
obtained from left over ammonium dichromate.
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| Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN |
Observations obtained using relatively high magnification microscopy during a kinetic study of the thermal decomposition of ammonium dichromate provided evidence that salt breakdown proceeds with the intervention of an intermediate liquid phase rather than a solid phase. The characteristic darkening of (NH4)2Cr2O7 crystals as a consequence of the onset of decomposition can be ascribed to the dissociative loss of ammonia accompanied by progressive anion condensation to Cr3O102-, Cr4O132−,etc., ultimately yielding CrO3. The CrO3 has been identified as a possible molten intermediate participating in (NH4)2Cr2O7 decomposition.
Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN 3 videos
Mercury
thiocyanate was formerly used in pyrotechnics causing an effect known
as the Pharaoh's serpent or Pharaoh's snake. When the compound is in the
presence of a strong enough heat source, a rapid exothermic reaction is
started which produces a large mass of coiling serpent-like solid. An
inconspicuous flame which is often blue but can also occur in
yellow/orange accompanies the combustion. The resulting solid can range
from dark graphite grey to light tan in color with the inside generally
much darker than the outside. This property was discovered by Wöhler in
1821, soon after the first synthesis of mercury thiocyanate: "winding
out from itself at the same time worm-like processes, to many times its
former bulk, a very light material the color of graphite...". For some
time, a firework product called "Pharaoschlangen" was available to the
public in Germany, but was eventually banned when the toxic properties
of the product were discovered through the death of several children
mistakenly eating the resulting solid.
and this experiment about
MERCURY-Filled Water Balloon - Science!
Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN 3 videos
Most amazing experiments chemical simple reactions Mercury, NH4Cr2O7 and HgSCN 3 videos
