Chemistry Reference
In-Depth Information
collected pneumatically and identified as hydrogen, if the reaction is started under
water.
Material: Glass dish, gas jar, cover glass, tweezers, wooden splint; bean-sized
pieces of lithium (C/F).
Procedure: The gas jar is to be filled with water and placed pneumatically in the
glass dish, which is half-full with water (see figure). A piece of decrusted lithium is
to be put with the help of tweezers under the opening of the gas jar. This procedure
can be repeated with more pieces of metal until the gas jar is filled with gas. With
the help of a cover glass, it is then removed from the glass dish and placed on the
working surface vertically. The gas from the gas jar is to be tested with a burning
wooden splint. Caution: there might be a little bang.
Notice: this reaction with sodium or potassium is very dangerous - the gas jar may
be destroyed during the reaction!
Observation: The vigorous formation of a colorless gas can be observed. The gas
burns with a bang at the beginning; the flame is red colored because of the presence
of lithium hydroxide solution.
E5.7: Reaction of Sodium with Chlorine
Problem: The reactivity of metals toward oxygen and water can also be assumed
regarding halogens. It can be shown exemplarily by the reaction of sodium and
chlorine. As an exception the reaction product sodium chloride can be tasted care-
fully. Interestingly the product of two aggressive and toxic substances is sodium
chloride - an essential nutrient!
Material: Gas generator, gas syringe with connected glass tube, test tube; potassium
permanganate (O/Xn), conc. hydrochloric acid (C), pea-sized piece of sodium (F/C).
Procedure: Chlorine is to be generated from potassium permanganate and hydro-
chloric acid in the gas generator under the hood; the gas syringe is to be filled
with chlorine and connected with a glass tube. The test tube is to be fixed (stand),
