Colourful chemistry with Andrew Szydlo #shorts #chemistry #experiment #science #lecturer

Added: 2026-05-21

[00:00:00]I have in my flask here 8 ml of mercury.

[00:00:04]You can see it there. I am going to react the mercury with concentrated nitric acid. Now, I'm going to pour in 20 ml of concentrated nitric acid. So, what I'm doing is this. The mercury is now going to be reacting with the concentrated nitric acid and it will be dissolving. It will be producing brown fumes. Now, that dark brown gas there is always produced whenever concentrated nitric acid reacts with anything and it's is a gas which is called nitrogen dioxide. It's a strongly acidic gas and as you see, the mercury gradually starts to react and gradually the nitrogen dioxide is going to go into here, into this absorption bottle here and then it's going to go into another absorption vessel here. The mercury will continue to react and can you see the bubbles are beginning to appear. Now, those are bubbles will shortly become more rapid.

[00:01:04]They will proceed more rapidly and the nitrogen dioxide gas will start to fill the container until you will see a significant amount of these dark brown fumes and they are strongly acidic. So, you see it's coming off here and they're going to go into here and they're bubbling through here. So, this is a sort of a waiting room where the gas can gather, but in this one here, I have got dilute ammonia solution, which is alkaline. So, because this is an acid, this is an alkali, they react together and now you see puffs of white smoke coming out. Now, that white smoke is the product of the neutralization of nitrogen dioxide with ammonia and that's ammonium nitrate, which is quite harmless. The purpose of these absorption flasks is simply to ensure that we don't have nitrogen dioxide going all over the front of the bench.

[00:02:06]It's not that dangerous, but it certainly is a very, very powerful irritant.