I built a conductivity meter from 9v battery, 3 pieces of electrical wire, light bulb, and put in solutions of salt,,baking soda, vinegar with cup of water. Light never came on but in salt water water swirled, turned brown, battery got hot. What did I do wrong?? Must take pics of each for the points.
Solution: To light up the need to form a galvanic system with two electrodes. In this case, the light bulb will be lit only in the case of salt and baking soda. It is these substances that dissociate in water to form positively charged and negatively charged particles: Na+ Cl- and Na+ HCO3-.