Calcium, reaction with water demonstration

Fig. 14 demonstrates a similar reaction of calcium carbonate with water ...

Reaction of calcium with water class practical or teacher demonstration... 

Bassam Z. Shakhashiri, "Preparation and Properties of Ammonia/ Chemical Demonstrations, A Handbook for Teachers of Chemistry, Vol. 2 (The University of Wisconsin Press, Madison, 1985), pp. 202-204. Ammonia gas is produced from the reaction of ammonium chloride with calcium hydroxide and is collected in an Erlenmeyer flask by the displacement of air. The ammonia gas turns moistened litmus paper blue, demonstrating the basic properties of ammonia dissolved in water. When the mouth of an ammonia-filled Erlenmeyer flask is placed below the surface of a pool of water, water rapidly enters the flask to replace ammonia that dissolves in the water. White smoke forms when ammonia vapor is passed over the top of a beaker of concentrated hydrochloric acid forming solid ammonium chloride. 

In vivo electron transport assays demonstrate that the site of Ca /Na action is Photosystem II. Ascorbate/DAD to methyl viologen rates (measured as O2 uptake) in the presence of DCMU are not affected by depletion of Ca " and Na" " while water to benzoquinone rates (measured as 2 evolution) in the presence of DBMIB show a decline concommitent with the loss of complete photosynthetic electron transport. Jji vitro examination of partial reactions within PS II reveals that the site of the cation effect excludes the water-splitting enzyme and occurs prior to the site of DCMU inhibition diphenylcarbazide-mediated silicomolybdate photoreduction after heat inactivation of the water-splitting enzyme shows diminished rates in membranes prepared from cells partially depleted of calcium and sodium. 

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