Measuring Density with Pycnometers, Hydrometers, and Graduated Cylinders

In this video, we delve into various methods and tools used in analytical chemistry to determine density accurately. Starting with basic techniques using graduated cylinders, we then explore more specialized equipment like hydrometers and pycnometers. We go through how to calibrate these tools and measure density with precision, even for irregular solids and powders. We also explore how the professional instruments work.

Donate to NurdRage!

[nnamrehck]

I am a retired analytical chemist. One mistake I noted was the lack of gloves when handling analytical glassware. Finger prints have mass and will change resuls in the second to the third decimal place depending on cleanliness of hands. Also, non-conducting liquids will suffer from static charges so an anti-static device is recommended. Otherwise your chemistry is excellent as ever Dr. Nurdrage!

[That_Chemist]

The flask grinding part was something I had heard about but I hadn't seen anyone actually do it - super useful

[vincejohnm]

I’m definitely a fan of flashy synthetic chemistry stuff, but I really appreciate the analytical deep dives. I always learn something new and analytical chemistry is in the “how the sausage gets made” territory of chemistry. Dreadfully unsexy but damned useful. Thank you for years of contributions to the science!

[tinsoldier]

As a non-chemist, I sometimes find these videos more interesting than your others. It feels like I'm legit learning something rather than watching a magic trick.

[andrewcloherty]

Non physical things such as minds, which can be exceptionally dense. Solid gold.

[appatula]

I vote for more additions like these basic educational principal segments to added to the NurdRage: "Lab Equipment" playlist! Even the boring simple things exactly like this become an incredibly interesting & motivating subject for the non or to-be aspiring home amateur chemist when NurdRage presents them! Teaching, learning and pushing personal boundaries is what this channel has been about since 2008!

[HeartCell]

When you started mentioning the "U-Tube density meter" I started thinking that youtube had some means of measuring the density of human minds.

[lexer_]

I am not any sort of chemist but I still find this kind of stuff super interesting. It's about human ingenuity and how people figured out interesting ways to solve problems and that is always interesting at least to me. I will probably never need to know how to do any of this but I like knowing it anyway.

[NotoriousSRG]

The mass of YouTube and the density are off the charts

[makegrowlabrepeat]

This is one of my favorite videos that you ever made and i have been watching since the beginning

[kyleeames]

As one who also enjoys maker channels, I couldn’t help but think when seeing the gas pycnometer and U tube device, “those are things that a lot of folks could make themselves if push came to shove.”

[billbrown]

Nurd Rage keep up these videos, one of the most credible sources of chemical techniques on YouTube and an added bonus you are a fellow Canadian!

[vanhalenman]

Its kinda crazy how much ive learned watching your channel for the past 14 years since i was a freshman in highschool, i wound up just doing HVAC lol. I still have a nice collection of mixed gold ive been piling up to turn into pure gold, im just waiting until i decide to invest in the proper equipment and build a ventilation hood.

[KallePihlajasaari]

Lovely video. These are great for ideas. A university auctioned off a gas type powder density instrument that I had my eye on for the nice vacuum pump, obviously others had a greater need and it went for a more reasonable price around EUR1000.

One great inline accessory for distillation is the parrot, it allows for continuous measurement of temperature and density of the distillate with a hygrometer and thermometer in a bottom fed overflowing cylinder.

[vincentbarnett]

Very much appreciate deep dives into the shallow end of the chemistry pool! 😂

It is good to have a reminder that even the most trivial elements can have great meaning and impact. 😊

Thank you, Dr. Nurdrage! 🧪

[domonikoldham]

genuinely excited to learn dude this is a topic i havent ever given much thought to thank you for the lesson :D

[beskamir]

I'm not a chemist, and I often get lazy/suck at calculating everything, but you've given me several ideas for how to finally determine the purity of my homemade KCl fertilizer.

In short, I used temperature solubility distillation to purify low sodium table salt (30% NaCl to 70% KCl) that I got for almost free, and while I assume I got it to around 90% pure, I don't actually have any data to back that up. All I did was dissolve as much salt as possible in boiling water (so around 97c where I live) and then cooled that solution down to as close to freezing as possible (around -20c). In theory, most of what precipitated out should have been KCl, but I've had no way of actually determining that analytically and didn't really care enough to figure it out on my own.

Now that your video's gone through all the details of how to accurately determine the density of a salt (both as a solution and powder, though I assume powder would be easier in my case?), I should have everything I'd need to figure out how pure my sample is just by throwing the observed density into this simple formula + densityOfKCl*(concentration) = observedDensity with concentration being what I'm after.

[mduvigneaud]

Thank you! This is so useful! Without knowing what I was doing I sorta fumbled my way through using a liquid that doesn't dissolve the various powder I was trying to measure. Pycnometers now added to my list of things I need to get.

[DicedIceBaby]

I also used to get irritated when employers would ask me to evaluate tedious things. Once I was asked to evaluate several thermal interface materials for their performance, and vocally griped about it to my boss. I later realized how utterly fascinating all of this was. It's just how it goes in science sometimes. Thanks for the great content!

[KurtCollier]

There is no good reason for me to watch this but I did. I feel smarter, though not in a way that is useful for my practical day to day life experience. I do not feel that my time has been wasted.