Below is a simplified diagram of a Down’s cell used for the manufacture of Sodium metal. Study it and answer the questions that follow.

Above is a simplified diagram of a Down’s cell used for the manufacture of Sodium metal. Study it and answer the questions that follow.

​a) Name the substance the anode is made of (1mk)

​Graphite

​b) Explain your answer in (a) above (1mk)

​Reject carbon

​Graphite does not react with chlorine liberated at the anode 

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​c) What is the role of the diaphragm in Down’s cell (1mk)

​To prevent metal and chlorine gas from recombining

d) In Down’s cell for the manufacture of Sodium metal, Calcium chloride salt is added to lower the melting point from 800⁰C to 600⁰C. Explain why it is necessary to lower the melting point (1mk)

​To reduce the cost of energy used to melt the sodium metal 

​e) Calculate the mass of sodium metal produced if a current of 50 amperes is passed through the molten Sodium chloride for two (2) hours (Na = 23, F = 96500C) (2mks)

​f) Below is a list of potential differences obtained when metal P, Q, R, S and T are used in the following electrochemical cell
Metal (s) / Metal ions // Copper (II) ions / copper (s) 

Below is a list of potential differences obtained when metal P, Q, R, S and T are used in the following electrochemical cell

​i) Which metal is likely to be Copper. Explain (2mks)

​R

​ii) Identify the strongest reducing agent (1mk)

​P

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​iii) Which two half – cells would be combined to produce the highest voltage? (1mk)

​P and T

​iv) Give a cell representation of the cell in F (iii) above. (2mks)

​P/p ions // T ions /T (s)