If the boiling point you measure during a distillation is lower than the literature value, it means that your sample is not as pure as it could be. There are a few possible reasons for this:
1) There could be impurities in your sample that are lowering the boiling point.
2) The distillation apparatus could be dirty, and this could be causing the boiling point to be lower than it should be.
3) There could be something wrong with the thermometer you’re using, and it could be giving a lower reading than the actual temperature.
4) There could be some other error in the experiment that you’re not aware of.
If you’re not sure what’s causing the lower boiling point, it’s best to repeat the experiment with a new sample and/or new apparatus to see if you can get a closer match to the literature value.
Other related questions:
Why is my boiling point lower than expected distillation?
One possible reason for this is that your boiling point may be lower than expected because your sample is not completely pure. If your sample contains impurities, they can lower the boiling point. Another possibility is that your equipment is not calibrated correctly. Make sure to check your equipment before beginning your experiment.
What does the boiling point tell you during a distillation?
The boiling point of a liquid is the temperature at which the liquid boils and turns into a gas. The boiling point tells you how much heat energy is needed to change the state of the liquid.
Does lower boiling point distill first?
No, the distillate is not necessarily in the order of boiling point. The most volatile components will distill first, regardless of boiling point.
Will the first ml of distillate collected be enriched in the lower or higher boiling point compound?
The first ml of distillate collected will be enriched in the lower boiling point compound.