REACTIONS OF METALS AND SULFUR
1
( A C h e ~Ed,
Submitted by: Noojin Walker, Pensacola Junior College, Pensacola, Florida Checked blj: Robert Bernoff, The Pennsylvania Stat,eUniversity, Ogontz Campus, Abington, Pennsvlvania 19001 PREPARATION
Obtain a large iron nail, a crucible containing a gram or so of powdered sulfur, a test tube three-fourths filled with a 1:1mixture of FP HCI and 0.1P SbCls.
REMARKS Fe
+S
-
FeS
DEMONSTRATION
Clean the nail by rubbing with steel wool, then heat the head of the nail to redness and touch it to the powdered sulfur. Allow the nail to remain in the ignited sulfur for 30-60 sec. (HOOD.) Remove the nail and allow the adhering sulfur to burn itself out. (HOOD.) Wash the nail with water. Suspend t,he nail in the HCl-SbC13 mixture and observe the precipitation of orange Sb&. Note the appearance of the nail.
The following questions might be asked of the student: Is hydrogel, pmd~tccd? Why does the nail beeamc shiny? Why did FeS not reprecipitate in eqn. (2)? Will all cat,iollsreact, similarly la Sh(III)? Why is Fe(I1) prodwed in eqn. (2) and not Fe(III)? Why did the nail become ~umwlallydark ahove the liqnid level?
Volume 45, Number 1 1 , November 1968
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A901
