Vladimir M. Petruševski
Ss. Cyril and Methodius University – Skopje (North Macedonia)
https://doi.org/10.53656/nat2021-3.02
Abstract. Generation of nitrogen dioxide is a well-known demonstration/experiment, usually performed by pyrolysis of Pb(NO3)2. In order to prevent obstructing the glass tubes or the test-tube where NO2 is generated, one may safely use a homogenized mixture of lead(II) nitrate and dry sand. Aesthetically it is not quite appealing, so during the same lesson a colleague experimenter decided to change the standard approach and to use table salt (sodium chloride) instead of sand. However, the result of the experiment turned to be a flaw! This appears to be one more proof for the correctness of the general experimenter’s philosophy: never improvise if you do not know the outcome.
Keywords: nitrogen dioxide; pyrolysis; lead(II) nitrate; sodium chloride; metathesis reaction