A gas handling device


Jersey. Checked by: Robert Varner, Clarkston High School, Michigan. PREPARATION ... made from a rubber stopper by cutting a wedge out of the big end...
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THE BROMlNATlON OF ACROLEIN Submitted by: H. N. Alyea, Princeton University, Xew .Jersey Checked by: Robert Varner, Clarkston High School, Michigan

PREPARATION

REMARKS

Obtain strips of bacon, a one-liter wide mouth flask, bromine, Bunsen burner and crucible tongs.

Cooking the bacon converts the glycerin portion of the fat molerules into acrolein, an unsaturated substance which gives the acrid fumes when fats are overheated. The presence of the double bonds is demonstrated by the decoloration of the bromine vapor as it is absorbed. The absence of acrolein in raw bacon may he demonstrated hy repeating the demonst,ration with a strip of raw bacon.

DEMONSTRATION

Pour bromine trapor (not liquid) into the flask until the flask is filled with the vapor. Cook the strip of bacon in the burner flame until reasonably rrisp. Quickly place the strip of bacon into the flask, stopper and shake. The color of bromine should rapidly disappear.

Journal of Chemical Educofion

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Augual 2980

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August 1980

A GAS HANDLING DEVICE Submitted bu: Clifford E. Lloyd. Orange Count~yCommunit,y College, ~ i d d l e t o w n New , York Checked by: Craig W . Larsen, Michigan Stat,e Universit,y, East. Lansing, Michigan

II

PREPARATION

Construct the glass pump shown in the diagram. The piston is made from a rubber stopper by cutting a wedge out of the big end. (Use a small sharp knife supported by a t,ool rest while the stopper is turning slowly in a lathe.) The piston is lubricat,ed with a watersoluble material such as glycerin. DEMONSTRATION

The pump is particularly useful: (1) In quantitative experiment,^ with gases such as hydrogen and oxygen. The volume of the gas may be measured by the linear movement of the piston. (2) In holding gas on tap for student use. Hydrogen sulfide has been successfully held in one of these pumps for a period of a week wit,hout. loss. (3) In collect,ing reactive and water-soluble gases such as ammonia and hydrogen chloride. (4) By using three or more of these pumps suitably connect,ed together, t,he volume relationships in t,he reaction between hydrogen chloride and ammonia may he shown.

Journol of Cbemieol Education