Letter to the editor

• The demonstration “Sharing chemistry with the community: The solubility and alkalinity of ammonia” by Kenneth Lyle and Penney Sconzo, Chem 13 News, November 2015 (pages 11-13) provides an excellent, colorful and safe version of the ammonia fountain.

However, in the second equation it tends to perpetuate the use of the obsolete nonexistent compound “ammonium hydroxide, NH4OH,” the name and formula of which still appears in raised glass letters on some reagent bottles.^1-4 No matter how the s and three p orbitals are hybridized, nitrogen can form a maximum of only four bonds. One of the reasons that the late John F. Baxter, Jr. and I advocated the use of "Hydrated Cations in the General Chemistry Course"² was to avoid the necessity of the use of NH₄OH in equations for the precipitation of gelatinous metal hydroxides by the action of aqueous ammonia on solutions containing hydrated metal cations such as Al(H₂O)₆³⁺, Mg(H₂O)₆²⁺, Cr(H₂O)₆³⁺, Zn(H₂O)₄²⁺, etc.

This photo of a loving Lego chemistry couple was sent in by Chris Miedema, Ashbury College, Ottawa, Ontario. The couple was put together from a variety of Lego sets with special effort to find goggles, Erlenmeyer flasks and a bushy beard.

References

1. John B. Davis, "Ammonia and 'Ammonium Hydroxide’", Journal of Chemical Education, Volume 30(10), October 1953, page 511.
2. George B. Kauffman and John F. Baxter, Jr., "Hydrated Cations in the General Chemistry Course", Journal of Chemical Education, Volume 58(4), April 1981, page 349.
3. Michael Laing, "There Is No Such Thing as NH₄OH", Spectrum, Volume 26(4), 1988, page 11.
4. John T. Yoke, "Ammonium Hydroxide Does Not Exist", Journal of Chemical Education, Volume 66(4), April 1989, page 310.