Lead-silver phase diagram

As shown in the zinc-silver phase diagram in Figure 12.9, there are five identified solid phases. The extremes a and r are solids solutions and there are three intermetallic compounds p, y and e. In practice the addition of molten zinc to lead bullion followed by cooling will result in the formation of these intermetaUics as solid precipitates, which are mainly of the e form but also contain r] towards the... 

In a eutectic reaction, as found in some alloy systems, a hquid phase transforms isothermally into two different solid phases upon cooUng (i.e., L + /3). Such a reaction is noted on the copper-silver and lead-tin phase diagrams (Figures 9.7 and 9.8, respectively). 

The two metals lead and silver mix together in the liquid form but do not form any chemical compound. The phase diagram is as shown in figure (4). It is explained as follows ... 

Another common eutectic system is that for lead and tin the phase diagram (Figure 9.8) has a general shape similar to that for copper-silver. For the lead-tin system, the solid-solution phases are also designated by a and /3 in this case, a represents a solid solution of tin in lead for (3, tin is the solvent and lead is the solute. The eutectic invariant point is located at 61.9 wt% Sn and 183 C (361 F). Of course, maximum solid solubility compositions as well as component melting temperatures are different for the copper-silver and lead-tin systems, as may be observed by comparing their phase diagrams. 

This is called the diagram of the cell and includes all of the components required to make experimental measurements of its properties. The single vertical bar represents a phase boundary. The two electrodes in the cell are the hydrogen electrode and the silver silver chloride, which are illustrated in fig. 9.1. The electrolyte solution is 1 M HCl in water. Each electrode is connected to a copper wire which is used as a lead to connect to the measuring device, for example, a voltmeter with a very high input impedance. Since the wires at the ends of the cell... 

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