The ordinary macro-Kjeldahl method was much improved in speed and reliability by using a mixed selenium–mercury catalyst with the usual potassium sulphate; but even in this case some doubt ...

Add 10 to 15 drops of glycerol to the depression in the center of a pile of finely ground potassium permanganate in an evaporating dish on a heat proof surface. Stand back! Within a few seconds, the ...

This process is sped up by a catalyst. In this reaction, the catalyst is potassium permanganate, and the bubbles are full of oxygen gas. Hydrogen peroxide decomposes on its own into water and oxygen ...

Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www ...