Summerlin & Early, Jr.
Chemical Demonstrations : A Source Book for Teachers
1st edition, 1985 sez —
60. Oxidation of Zinc: Fire and Smoke
1. Cl- (from NH4Cl) acts as a catalyst on the decomposition of NH4NO3
Cl-
NH4NO3(s) --> N2O3(g) + 2H2O(aq)
2. Water produced in the reaction causes the decomposition of more NH4NO3 (autocatalylic effect).
3. The reaction melts the NH4NO3 and allows the oxidation of the zinc. The overall reaction is probably as follows:
Zn(2) + NH4NO3(s) --> ZnO(s) + 2H2O(g)
B Shakhashiri's Chemical Demonstrations : A Handbook for teachers of
chemistry, provide a few more details.
By da — in the second ed of Summerlin & Early the entire "Explosion, Smoke, Fire" sections was eliminated. This experiment was not in that section.
Vol VIII Sup 1 p. 545 [1964] of Mellors opus provides more info on the catalytic effect of chlorides on ammonium nitrate. [sited in Shakhashiri, shelved by Id.]
