Mar 7, 2018
Copper acetate (Hoganite) made in the lab by evaporation of a solution of copper metal in white vinegar to which drops of hydrogen peroxide were added.
seen from Finland
seen from Pakistan
seen from Finland
seen from United States
seen from Russia
seen from Russia
seen from United Kingdom
seen from India
seen from China
seen from Russia
seen from Israel
seen from Indonesia
seen from Israel
seen from Russia
seen from Germany
seen from United States
seen from Poland
seen from United States
seen from Bosnia & Herzegovina
seen from Russia
Copper acetate (Hoganite) made in the lab by evaporation of a solution of copper metal in white vinegar to which drops of hydrogen peroxide were added.
Beautiful crystals of glycoluril, formed by slow reaction between urea and glyoxal in water.
Glycoluril has been used as a slow-release fertilizer, and is the precursor of a type of macrocyclic structures called cucurbiturils.
Explosive in a test tube: the heptoxide of manganese is a very unstable and elusive substance. Pure is a red liquid very explosive, but it could be visualized safely by this experiment: put a layer of 2 cm of methanol on the same volume of concentrated sulfuric acid (very corrosive). Add a few crystals (not powder) of potassium permanganate. The sequence of reactions is:
KMnO4 + H2SO4 –> HMnO4 (violet color)
HMnO4 + H2SO4 —> [(MnO3)2-SO4]
[(MnO3)2-SO4] —> MnO3+ + HSO4– (green color)
MnO3+ + HMnO4 —> Mn2O7 (brownish red)+ H+ —> MnO2 (brown)+ 3 O —> O2 + O —> O3
The decomposition of manganese heptoxide is explosive in presence of organic matter. So, the explosions in the interface between acid and methanol.
Potassium permanganate titration of iron