It is now understood that dissolving-metal reactions occur at the metal surface, and the concept of nascent hydrogen has been discredited in organic chemistry.
[1][2] However, the formation of atomic hydrogen is largely invoked in inorganic chemistry and corrosion sciences to explain hydrogen embrittlement in metals exposed to electrolysis and anaerobic corrosion (e.g., dissolution of zinc in strong acids (HCl) and aluminium in strong bases (NaOH)).
[5] Franchot published a paper on the concept in 1896,[6] which drew a strongly worded response from Tommasi who pointed to his own work that concluded "nascent hydrogen is nothing else than H + x calories".
In the Marsh test, used for arsenic determination (from the reduction of arsenate (AsO3−4) and arsenite (AsO3−3) into arsine (AsH3)), hydrogen is generated by contacting zinc powder with hydrochloric acid.
Acid conditions in the Marsh test promote the fast escape of the arsine gas (AsH3), while under hyperalkaline solution, the degassing of the reduced ammonia (NH3) is greatly facilitated (the ammonium ion NH+4 being soluble in aqueous solution under acidic conditions).