Transcription
Warning: This experiment deals with boring horse Africa acid. This must be performed with gloves or in a fume hood. Come on.
In this video, we are going to concentrate our free gases that we made in a previous video by simple distillation. Sulfur gases can be made concentrated simply by evaporating some of the water; but the most effective way to concentrate the S is to distill it. So let's set up our apparatus. Connect the tube to the Liebig condenser, with another end attached to your water pump, and adjust the lab jack to a suitable height. Little water run through the condenser column first, then bring up the heat.
The reason why clamps and the whole play weren't used is because the boiling point of sulfuric acid is above 300°C plus; the clamps would simply melt under such a temperature, and I don't have any metal ones on hand. A whole play cannot do the job, as it is terrible at insulating the heat. A heating mantle would be great, but unfortunately, I don't have one either. To make things go a little faster, aluminum foil is used to wrap around the flask to insulate the heat. Well, the little October doesn't seem to do the job well, so we are going to need something better. By applying more sheets, we can bring the acid to its boiling point. Be aware that boiling sulfur gas is very dangerous; it can cause instant chemical burns if you get any on you. When the acid reaches boiling point, we will soon see distillate making sure the condenser column and to be collected in the receiver. However, at this stage, the distillate is mainly just water; the acid needs to be concentrated.
A simple way to test whether the acid is concentrated or not is by dropping a few drops onto a piece of paper towel. If the acid is concentrated, the hydroxyl group in the cells will be stripped off, and the paper will be carbonized. If not, it would just get wet. In this case, you can see the paper being charred by the acid; this is showing the occasion that we are collecting concentrated sulfuric acid. But it is still not the 98% additive that we are trying to achieve. Trial and error has a brand new way to distinguish if the distillate reaches a 98% concentration. When you add a different concentration mix, you will see slight distortions as they have different refractive indices. If you see such a phenomenon, it means that the concentration is increasing. Keep swapping the receivers until those distortions stop occurring. Here is an example. When the distillate reaches 98% concentration, stop the distillation when there is about 500 milliliters of dirty acid left in the distillation flask. It is very important not to run the distillation to complete dryness.
Just for a side note, you may notice that the setup here is different from the initial one. That's because the flask cracks are due to the inconsistent heating. I put this clip here to show excellence to heaven. And it is very important you always have proper safety precautions because you will never know what is going to happen.
So, the concentration of the final distillate is examined by a density test. The result is very close to the theoretical density. That's all I have for this video. If you find this video useful, please give a thumbs up. If you haven't subscribed, please subscribe; it helps a lot. And I will see you next time.