Does voltage/current affect the temperature of the solution in electrolysis?
I was performing an experiment investigating the effects of solution temperature on the electroplating rate of zinc, using 0.75 mol/L zinc nitrate hexahydrate solution, zinc strip wired to the positive terminal and an iron nail wired to the negative terminal. I set the voltage to 5 volts, and the current to around 2 amps. However, I found that the solution temperature significantly increased during electrolysis - from 20 to 90 degrees Celsius. My teacher didn't know what was happening, and neither do I. I clearly need to modify my experiment aim, but is there anything I can salvage out of this mess? Such as looking into the effect of voltage on solution temperature? Also why does the temperature increase?
TL;DR: Electroplating of zinc with a zinc nitrate hexahydrate solution increased temperature of solution from 20 to 90 degrees Celsius. Why does this happen? And does voltage affect the temperature?
I was performing an experiment investigating the effects of solution temperature on the electroplating rate of zinc, using 0.75 mol/L zinc nitrate hexahydrate solution, zinc strip wired to the positive terminal and an iron nail wired to the negative terminal. I set the voltage to 5 volts, and the current to around 2 amps. However, I found that the solution temperature significantly increased during electrolysis - from 20 to 90 degrees Celsius. My teacher didn't know what was happening, and neither do I. I clearly need to modify my experiment aim, but is there anything I can salvage out of this mess? Such as looking into the effect of voltage on solution temperature? Also why does the temperature increase?
TL;DR: Electroplating of zinc with a zinc nitrate hexahydrate solution increased temperature of solution from 20 to 90 degrees Celsius. Why does this happen? And does voltage affect the temperature?
1 Answer
I’m no physicist but I should imagine that the temperature rise is due to the resistance of the solute in the circuit.
Explanation:
More resistance in a circuit results in greater heat produced (energy is transferred from electrical energy to heat energy). The greater the current in a circuit, the greater the effect of resistance (essentially energy is used to ‘force’ units of electricity (coulombs) through a bridge of resistance) and so thus more energy (temperature) is given off.
