Summary

Catalysis

Source Archive Films by Getty Images
Title: Catalysis
File Number: DN-S-050 1 inch
Color: B W
Type: Educational
Year: 1937
Subjects: ANIMALS PLANTS CHEMICALS REACTIONS SCIENCE CATALYSTS CHEMISTRY RUBBER GASOLINE PETROLEUM ENERGY
Description: B W 1937 Catalysis DESCRIBES FUNCTIONS OF CATALYSTS IN CHEMICAL REACTIONS. EXPLAINS HOW THEY MAY ABSORB OR ACTIVATE MOLECULES, FORM INTERMEDIATE COMPOUNDS OR START A CHAIN REACTION. SHOWS THEIR USE IN THE MANUFACTURE OF RUBBER & GASOLINE & RELATIONS TO PLANTS & ANIMALS Contents. Properties of catalysts, and several industrial applications of catalytic action, demonstrated by animation and straight photography. Begins with views of a chemical plant as the commentator calls attention to the use of catalysts in modern industry. The effect of a catalyst, manganese dioxide, upon heated potassium chlorate is demonstrated. The phenomenon of adsorption is demonstrated with the use of metallic palladium and hydrogen gas. The commentator states that in most cases the catalyst not only adsorbs but activates the molecules. Catalytic activation and surface reaction are demonstrated by animated diagrams. A catalyst is introduced into two substances that normally react very slowly. The substances are represented by units shaped like barbells, and the catalytic agent is represented by peaklike units at the bottom of the drawing. The commentator states that because molecules tend to be adsorbed on the peaks their atoms may be pulled farther apart by the catalyst, thus weakening the bonds that hold them together. Further animations illustrate how the reaction is stopped by the poisoning of the catalyst. Catalytic action in gases and solutions is demonstrated by the addition of cupric ions to sodium sulphite and oxygen. The commentator states that in reactions of this type the catalyst often acts in the formation of intermediate compounds. This analogy is demonstrated by showing that in a basketball game it is sometimes quicker to pass a ball through an intermediate player than to pass it directly. Further animation shows the function of a catalyst in forming intermediate compounds and facilitating reactions. The use of negative catalysts in preventing rapid oxidation and hardening of rubber is described. The effect of an inhibitor, hydroquinone, on the rate of reaction between benzaldehyde and oxygen is demonstrated. More complex chain reactions are demonstrated with the use of hydrogen and chlorine. In a darkened room this mixture does not react but, when it is exposed to light, it explodes. Animations indicate the steps by which this chain reaction occurs and is broken. The use of tetraethyl lead to eliminate gasoline engine knock through breaking chain reactions is demonstrated. The film closes with views illustrating practical applications of catalytic action. Appraisal. Reported very good for (1) explaining the nature of catalytic action and (2) indicating the importance of positive and negative catalysts in making possible many chemical processes essential to modern life. It was reported that the animated diagrams presented concepts dealing with catalysis more clearly than they could have been presented by other mediums of instruction. Since the subject and its presentation is somewhat advanced, some study of the topic should precede the showing. Photography and sound are excellent.
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