Copper in Concentrated Sulfuric Acid
Copper turnings are dropped into a flask. Sulfuric acid is added, and the mixture is heated.
The heated air expands, and is pushed out of the flask. The copper reacts with the acid. One of the products is sulfur dioxide gas, which fills the flask.
After the heat is removed, the gas in the flask cools, and contracts, drawing water into the flask. Initially, the water vaporizes due to residual heat, and expands rapidly. Again it cools, and water is drawn again into the flask.
As water enters the flask, the sulfur dioxide gas evolved in the reaction dissolves. The pressure in the flask is reduced, which draws more water into the flask.
When a concentrated solution of ammonia is added, the copper(II) ion in solution reacts to form a complex ion, which is blue in color.
The size of the movie file is 8.1 MB and its duration is 120 seconds. The name of the movie file is "CUNASID.MOV" and it is located in the folder "MOVIES/CUNASID".
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