In the electrolytic cell, there is a power supply. The direction of current flow is from the positive electrode of the power supply to the negative electrode of the power supply, while the direction of electron flow can be opposite.
When scientists discovered current, they defined current as the direction of flow of positive charges. In establishing this definition, scientists did not know that electrons carry negative charges, so the direction of current flow is opposite to the direction. of the flow of electrons.
In an electrolytic cell, there is a power supply. The direction of current flow is from the positive electrode of the power supply to the negative electrode of the power supply, while the flow of electrons is in the opposite direction. direction. In the primary battery, the primary battery is equivalent to the power supply. The direction of current flow is from the positive electrode of the primary battery to the electrodenegative of the primary battery, while the direction of electron flow is in the opposite direction.
Reaction rules
Anode: active metal - the electrode loses electrons (except Au, Pt
Inert electrode - in solution); Anion electron loss
Electron loss capacity: active metal (except Pt, Au)>S2->I->Br->Cl->OH->oxyacid radical (NO3->SO42 -)>F -
Cathode: The ability of cations in the solution to obtain electrons: Ag+>Hg2+>Fe3+>Cu2+>H+ (acid)>Pb2+>Sn2+>Fe2+>Zn2+>H+ (water )>Al3+>Mg2+> Na+>Ca2+ >K+ (i.e. the reverse of the metal activity sequence table)
Rule: ions before aluminum (containing aluminum) do not discharge, the ions after hydrogen (acid) discharge first, the ions before hydrogen (acid) and after aluminum see state.
Reference for the above content: Baidu Encyclopedia - Electrolytic Cell
How to Make a Hydrogen Balloon
1. diameter of 7.5 cm Add three quarters of the water.
2. Add a spoonful of salt to the water. Salt can help conduct electricity (although chlorine gas is produced during electrolysis due to the addition of chloride, as long as the current is not very large, the amount of gas impurities will not be important).
3. Cover the glass with cardboard. Then insert two wires 30 to 60 cm long onto the cardboard spaced about 5 cm apart, and let the part of the wires 5 to 7 cm long be immersed in the water.
4. Connect the other end of the wire to the positive and negative poles of the 9-volt power supply. Soon you will see bubbles forming near the wire in the water, hydrogen is produced at the negative electrode and oxygen is produced at the positive electrode.
5. If you want to prepare a large amount of hydrogen or oxygen, you can perform the following steps as appropriate, otherwise proceedsimply step 5. You will need a small container (a syringe is best) and something to hold the container upside down (usually tape).
6.Immerse the small container in the glass. Do not take the small cup out of the water. Remove it or place the mouth of the small cup upwards, but turn the small container over so that the mouth of the small container contacts the bottom of the large cup (if using a syringe, you just insert the small opening of the front end of the syringe into the water, then remove the core) Stem, just fill it with water, then go straight to step 9).
7. Slowly pull the small cup up, but don't let the water out. The end effect is that the small cup protrudes above the water and is filled with water (the pressure causes the water to stay inside the small cup).
8. Use tape, clips, etc. to fix the small cup.
9. Insert the positive and negative poles of the wire into the small container.
10. When the small container is filled with gas, it can be removed. In high temperature processing of glass manufacturing and electronic chip manufacturing, hydrogen is added to the nitrogen shielding gas to remove residual oxygen.
4. Used as a raw material for the synthesis of ammonia, methanol and hydrochloric acid, and as a reducing agent for metallurgy.
5. Due to the large fuel capacity of hydrogen, the aerospace industry uses liquid hydrogen as fuel. For reference only
The proportion of ingredients is one and a half pounds of aluminum powder: 2 pounds of caustic soda: 7 pounds of cold water Separate the aluminum powder and caustic soda in a food bag and put 1. serving of each according to weight for later use. First put the soda caustic. Then put in the aluminum powder, then pour in the water, quickly screw the bottle cap, then use a wrench to tighten the screws. the cap;
When producing hydrogen, be sure to close the gas nozzle to avoid creating hydrogen. In summer, because the temperature is too hot, it must be cooled after 10 o'clock. -15 minutes. Cooling method: pour cold water on the bottle to achieve the cooling effect. Continue pouring water for 3-5 minutes to cool. After cooling, it can be filled 7 to 8 minutes after cooling.
Detailed information
Danger: As hydrogen is cheaper than inert gases like helium, hydrogen balloons are mainly sold on the walk. Hydrogen can easily explode or burn when it rubs against other objects to generate static electricity and when exposed to open flameses. In addition, most of the colorful balloons sold by sellers in the market are hydrogen balloons filled with hydrogen. The safest are helium balloons filled with helium.
When using hydrogen balloons, please note that static electricity generated by friction between hydrogen and other objects and exposure to open flames, high temperatures and Electric sparks will cause the flammable and explosive hydrogen to burn and explode.
Baidu Encyclopedia - Hydrogen balloon