Silver electroplating

BS 6669 Methods of test for electroplated Silver and Silver Alloy Coatings... 

Research the commercial process of electroplating silver in the costume jewelry industry. Write a sununary of your findings, including a diagram. 

Batteries were probably used more than 4000 years ago. It is believed that Parthi-ans used batteries to electroplate silver (Baghdad, 250 B.C.), and also that the Egyptians were able to electroplate antimony onto copper more than 4000 years... 

Silver selenite was prepared by addition of a selenious acid solution to a solution of silver nitrate. The product was recrystallised three times from nitric acid ( ). Sodium hydrogen selenite solution was prepared by neutralisation of recrystallised selenious acid by carbonate-free sodium hydroxide. The silver-silver selenite electrodes were obtained by first electroplating silver onto a platinum foil and then converting some of the silver to silver selenite by further anodic electrolysis. The procedure was apparently the same as used for the preparation of silver-silver chloride electrodes. The experiments were carried out in the dark or in subdued daylight. 

Reduction is often seen as the gain of electrons. In the process of electroplating silver onto a teapot (see the section, Five Dollars for a Gold Chain Electroplating, later in this chapter), for example, the silver cation is reduced to silver metal by the gain of an electron. The following equation shows the silver cation gaining the electron ... 

Electroplating silver onto Silver anode a teapot. 

Figure 8.11. Electrochemical cell for electroplating silver onto copper.

Filiform corrosion under organic coatings is common on steel, aluminum, magnesium, and zinc (galvanized steel). It has also been observed under electroplated silver plate, gold plate, and under phosphate coatings. 

Figure 37. Absorption spectrum of electroplated silver on substrates (Top), fluorescence emission specta of ICG-HSA on ITO and silver deposited on ITO (Bottom) Adapted from 48.

In the 1930s, electrochemistry was a major part of physical chemistry and laboratory measurements were related to easily reproducible experiments. Thus plating out 1 mole of silver metal from a solution of AgNOa was an easy way to measure coulombs with an ammeter to measure current and a clock measuring seconds. The Faraday constant then requires fiufher definitions of an ampere etc., but those constants can be obtained through measurements and calculations from electroplating silver. Today, the modem values are all subjected to a least squares fit of all the known constants with the best experimental data except, as mentioned above, the value of c is now fixed and not subject to further measurement. The value of c is the kingpin of most of all the other constants. 

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