Electricity can be made when certain chemicals react together. We usually use chemicals to make electricity for example on a flashlight, a clock battery or sometimes a car battery. There are cars that run on electricity! Devices that store electricity are called batteries. Instead electricity can also be used to produce chemical changes or so-called electrolysis processes.
Water is a simple chemical made from two gases – hydrogen and oxygen. Each water molecule has two hydrogen atoms for each oxygen atom. H2O is the chemical formula for water molecules.If an electric current is passed through the water between the electrode (positive and negative of the battery pole), then the water will be divided into two parts: oxygen and hydrogen. This process is called electrolysis and is used in industry in many ways, such as making metals such as aluminum. If one of the electrodes is metal, then the metal will be covered or coated with metal in solution. or so-called electroplanting or plating process.
We can use electricity to make hydrogen gas from water similar to a process called electrolysis.
Equipment and materials
1. A 9 volt battery (can arrange 1.5 volt battery)
2. Two pencils
4. Thin cardboard
6. Small glass
1. Sharpen both ends of the pencil.
2. Dissolve about one teaspoon of salt into warm water and let stand for a while. Salt helps to conduct electricity better in water.
3. One part of one end of the cable is connected on the positive side of the battery and the other end of the cable to the black graphite at the top of the pencil. Do the same for the negative side to connect it to the second pencil.
4. Cut the cardboard according to the size of the glass.
5. Put two pencils into cardboard, about one inchi apart.
6. Place the other ends of the pencil into the salt water.
Results and Discussion
The electric current from the battery passes between two electrodes (pencil), the water is divided into hydrogen and chlorine gas, which collects the bubbles as very small around each end of the pencil.
Hydrogen collects around the cathode (negative pole) and the chlorine gas collects around the anode (positive pole).
How can we get chlorine from H2O? Because in this experiment we use salt then chlorine gas out of the salt or NaCl
Oxygen can not exit this experiment. That’s because the oxygen atoms from the water combine in liquids with salt to form hydroxyl ions. The chemical formula of salt is NaCl or sodium chloride. Chlorine gas from chloride in salt. Oxygen in hydroxyl ions resides in solution. So, what happens to this reaction is not oxygen but the chlorine gas that collects around the tip of the pencil. Around another pencil is hydrogen gas.
To make Oxygen from water in this way can use water without salt or use aquades, but of course the electrolysis process is not as fast as when using salt as a help conductor of electricity in water