Dangerous Mixture: Trimethyl Phosphite and Magnesium Perchlomte
To the Editor: I n the interest of safety to your readers, the following report of a high-potential chemical accident is submitted for your information. Fortunately, the accident resulted in only minor injury to the employee, but it had every potential for very serious injury. The Accident
Using this procedure 130 students obtained preparations containing 65.6 =t4.0% Ni versus 64.8% theoretical for NiS. Professor Crouch found 64.4 + 1.8% Ni on four samples. The identification of the nickel sulfide powdered sample was achieved through the interpretation of its X-ray powder diffraction pattern. It was found that the observed relative intensities and d-spacings corresponded to those of nickel sulfide, NiS, as reported in the ASTM files, card catalog #2-1280. This corroborates previous analytical evidence supporting the claim that careful heating of Ni metal with S powder in a crucible will produce NiS alone. X-Ray powder photographs were taken a t room temperature (-25'C) with a Picker camera of 114.6-mm diameter and Ni-filtered Cu radiation (KG = 1.54178 A) produced on a Philips X-ray generator set for an exposure of 24 hr at 35 kV and 19 ma. The powder diffraction data, as corrected for expansion of the film during processing, are listed in the following table with the values reported for NiS on ASTM card #2-1280.
The employee was mixing solutes with organic solvents and measuring their physical properties in making a study of organic electrolyte systems for electrochemical power supplies. The work was being performed inside a ventilated hood, but the safety glass shield a t the front was left open approximately 10 in. to permit access of the employee's hands to his work. He was pouring trimethyl phosphite, (CH30)sP,from an open beaker into a 25-ml volumetric flask containing approximately 0.5 g of dry solid magnesium perchlorate, h'Ig(CIOn)p. Both the beaker and flask were being held in his hands. (He was wearing rubber gloves.) The instant the trimethyl phosphite came in contact with the magnesium perchlorate, therewasanimmediate flash followed by a loud report which was beard throughout the building. The employee received deep cuts on his hands and superficial cuts on his face. One lens of his safety glasses was shattered, which indicated that the glasses possibly prevented a serious eye injury. I n the investigation, it was learned that a thorough literature study had been made and the oxidizerorganic solvent reactions examined. In none of the literature was the hazard of explosion mentioned. This explosive reaction has been verified by repeated small-scale duplications of the above-described incident. This work was supported by the United States Atomic Within experimental error, the compound is NiS. Energy Commksion. No additional lines were observed to indicate impurities were present. The last seven lines could not be L. M. JERCINOVIC D. L. R o s ~ measured due to the fact that part of the diffraction pattern was not present on the film. SANDIA CORPORATION The weights and X-ray analysis are very convincing S A N D BASE,; ~A ALHUQUERQUII, NEWMKXICO 87115 evidence for NiS being the sulfide formed in this experiment.
Prepamtion of Nickel Sulfldes
To the Editor:
A note by Dingledy and Barnard [J. CHEM.EDUC., 44, 693 (1967)l reports the preparation of Ni3S2by the methods often used for preparing CuzS in the iutroductory chemistry laboratory. This is contrary to our experience with nickel by students and lab instructors a t both Swarthmore College and the University of Illinois. We find that with the following procedure NiS is obtained. Heat 1 g of powdered nickel mixed with 1 g of sulfur gently in a. covered crucible until flames of burning sulfur dissipate and then to red heat. Cool and weigh. Add 0.5 e of sulfur and repeat the heating, cooling, and weighing cycleuntil eonstant weight is achieved.
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Journal of Chemical Education
To the Editor: The method of Cullen, Crouch, and Haight is not exactly that used to prepare copper sulfide in the laboratory, and therefore d i e m from that described by Dr. Barnard and myself. It seems that the critical difference is the addition of more sulfur after the initial heating, leading by favorable transformation kinetics to the narrow aNil-, S solid solution phase region shown by Kullerud and Yund [J.Petrol, 3,126 (1962)],
