I'm a new chemist and my boss wants me to find out the boiling point of the solvents from a mixture. Before the distillation is done in bulk in the big heater tank, I have to do it on a small scale in the lab to check the boiling point of the solvents.
From the theory, when a liquid starts to distillate, the temperature should be constant until all the liquid comes out and then the temperature starts rising again until the second liquid with the higher boiling point condenses.
The problem is the temperature is not constant when the first distillate condenses (temperature keeps rising even when the solvent is being distilled out) and then it fluctuates. After 140 C the temperature drops to 80 C and then rise to 140 C
I repeated the second time and the 1st distillate is around 70 C and 2nd distillate around 155 C..
So the bottom line is why the temperature is not constant even when it starts condenses??