Memoirs of the Faculty of Education, Shimane University. Educational science

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Memoirs of the Faculty of Education, Shimane University. Educational science 1
1967-12-28 発行

理科実験における「水の電解」の取扱い

Experiments of "Electrolysis of Water" in Science Education
Sagawa, Noriko
Itoh, Yoshiki
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Description
Hitherto, in the experiment of electrolysis of water, we had-confimed that the generating gaseous body was hydrogen and oxygen and also as the ratio was 2:1, we have used the symbol H_2O to explain the composition of water. As platinum plates are expensive it is difficult to use them in experiments by pupil and lead and nickel plates have been substituted in place of platinum plates. Past research undertaken were mainly to show that even when these plates were substituted, the ratio was 2:1. But, the result obtained after a thorough experiment was made was that even when lead and nickel were used they did not always give the ratio of 2:1 due to part of the dissolving gas reacting to the electrode plate and also due to their dissolving in the solution.
Electrode plates, other than these used did not always give the ratio of 2:1. In confirming this, having simultaneously acknowledged the fact, that through guidance in the experiment of electrolysis of water. We investigated the principles and laws that have to be understand, and the techniques of experiment to be carriedout byhe pupil. Our study was from this standpoint.
As a result, we haye reached the conclusion that the following points in guidance are possible :
1. A part of the gaseous body always dissolves.
2. When the platinum piate is used, the ratio of hydrogen and oxygen 2:1 usually occurs.
3. In the case of lead and nickel plates, it cannot be said that generating occurs in Proportion to quantity of electricity.
4. In using electrode plate generally used (other than platinum, lead, nickel, etc.) hydrogen and oxygen generates. In electrode plates, oxydation-reduction is confirmed.
5. In electrode plates generally used, the quantity of generating gas occursin proportion to electric current and time.
6. Even with electrode plates generally used, the quantity of generating gas have no relation to the distance, variety, area and the concentration of electrolysis solvent of electrode plate.
7. After complete oxydation-reduction by turning on the electric current beforehand to the quantity of generating gas, lead and nickel electrode plates, the quantity of generating gas from the electrode plates is of complete unity with the theoretical value estimated from the electric current.
NCID
AN0010792X