Synthetic Inorganic Chemistry

SODIUM HYDROXIDE BY ELECTROLYSIS 187

coming this than in bringing about the electrochemical change
itself. Hence, we shall not even measure the voltage drop across
the cell to determine the power efficiency, but we shall frankly
limit our problem to a study of the current efficiency.
Materials: saturated sodium chloride solution,
saturated copper sulphate solution,
standard acid and base,
phenolphthalein solution,
reagent alcohol.
Apparatus: two 8-inch U-tubes.
2 burette clamps.
2 copper electrodes,
iron electrode,
carbon electrode,
brass connector.
100-watt lamp and socket,
ring stand,
cotton wool.
2 burettes.
Data Form:
Duration of Experiment Hour Minute Second

1. Ended (lamp unscrewed)


2. Begun (lamp screwed in)


3. Time elapsed minutes seconds


4. Weight of copper anode, before grams


5. Weight of copper anode, after grams


6. Loss in Weight grams
   Titration
   HC1


7. Normality of HC1 solution


8. Burette reading after titration cc.


9. Burette reading before titration cc.


10. Number of cc. used in titration cc.
    NaOH


11. Normality of NaOH solution


12. Burette reading after titration cc.


13. Burette reading before titration cc.


14. Number of cc. used in titration cc.