Other experimental methods for water electrolysis

Device I
Use a 500 ml beaker as an electrolyzer. The electrodes are made of thick copper wire covered with plastic tubes. Each end is exposed 2 cm and bent into a hook shape. One end is buckled on the beaker, and the other end is used as an electrode. Use 15% sodium hydroxide solution as the electrolyte and two test tubes of the same size as the air collecting tubes. Since sodium hydroxide solution is corrosive, you can first fill the test tube with sodium hydroxide solution, cover it with a piece of tissue paper and turn it upside down. Because the atmospheric pressure is stronger than the pressure of the liquid in the test tube, the paper will not fall. Insert the test tube upside down under the liquid surface, use tweezers to remove the paper, put the test tube on the electrode, and fix the test tube with cardboard with two round holes. During electrolysis, when a DC power supply of 6 to 12 volts is connected, many bubbles will appear on the two poles. After 3 minutes, about 16 ml of hydrogen can be obtained at the cathode, and about 8 ml of oxygen can be obtained at the anode.
To test the obtained hydrogen and oxygen, you can bend one end of the thick iron wire into a circle, put a piece of cardboard on it, place it under the mouth of the test tube, take it out, and then test it after standing it upright.
Device II
A large salt water bottle with the bottom cut off is used as an electrolytic cell, and the electrodes are made of two thick copper wires passed through a rubber stopper. In order to limit electrolysis to a small area, a bottleneck is used as an electrolyzer. First, fill the bottle with water 3 to 4 cm higher than the electrode, then use a long-neck funnel to inject 15% sodium hydroxide solution into the bottom of the bottle neck, and squeeze the clean water to the upper layer. Fill two test tubes of the same size with clean water and stand them upside down above the electrodes, then turn on the electricity and conduct the experiment in the same way as above. This method is more convenient to operate.