Pycnometers Made Easy--The Best Way to Measure Density! By Dr. Shawn

[@AnthonyFrancisJones]

Excellent explanation. I have used the old ones that were hidden away in a dusty cupboard for years with young students and they enjoyed both the understanding of density and comparisons of distilled and salt water.

[@Totalscience569]

Chemist, thank you so much for this video because tomorrow is my oral test about this topic... And now able to given my ans and perform the practical carefully.... God bless you sir..

[@MinaiUsagi]

christ, THIS IS SO EASY TO UNDERSTAND! All my school materials make it more complicated than necessary! Thank you very much for the video!

[@alexhannon9467]

This is presented with beautiful clarity. Two different values are given for the density of water at 23 centigrade, and I think the right value is 0.99753 g/cc.

[@grahamwilson8843]

I really appreciate that you made this! A perfect way to know what I'm doing going into the density lab in chemistry class. Thanks!

[@denniswhv7546]

Thanks for teaching me this unit in ~9 mins, You helped me out here. Greets from Germany.

[@citizenscientistsworkshop1948]

My pleasure! I hope you subscribed to my channel.

[@omarino99]

This video is perfectly clear. Congrats and thank you

[@aldoizaguirre3551]

The best thing about this video is that he uses SI units, Thank You.

[@nurbanuyanar5479]

That is such a creative video! Fun to watch, and I understand it very well. Thanks!

[@tristanchristensen5963]

Great job explaining! Time to kick ass tomorrow at lab

[@hulinwei5915]

very very easy to understand! Thank you for sharing this video!

[@sreylensaing182]

This video is very helpful for Food Science and Technology students like me. Thanks! Please keep producing more videos.

[@brunovelasque8951]

Wow this video is super helpful! You explained the subject well in a short and concise manner. Thank you so much!

[@virendrasrivastava2702]

Done exactly same as written in my physics book Perfection😲😲😲😲

[@kamalakarpullamraj7256]

thank you Mr.Carlson

[@aalkhasha2023]

I am Arafat alKhasha from Yemen. I have PhD in Soil Science from King Saud University last April. I am looking for a job, thank you.

[@mdatiqurrahman9951]

Incredible explanation- must appreciate that. 🤗

[@isaacblep9875]

Just perfect! thanks from Panamá

[@jijijuju113]

Great class sir

[@johnmiller0000]

Very clear - thank you. I'd love to see this done in Imperial units just for the pain of it.

[@wessonsmithjr.6257]

FYI if you need to measure something that dissolves in H2O but not ethanol use ethanol as the medium instead. Just need to know the density of the ethanol first. I suppose you can use any liquid once you know it's density.

[@citizenscientistsworkshop1948]

You are of course correct. Thanks for the input!

[@anikislam8507]

awesome. thanks from Bangladesh

[@zillurrahman2706]

How can I get the density of powdered particles? Thanks for the video, it is very helpful.

[@NuwanPushpakumara-jn6qq]

Thank for lesson, it's really help for me

[@achalawithanage7141]

Thank you,great explanation✨️

[@dellainesrine3197]

thank you, sir, this video helped me a lot.

[@sailormoonz9896]

PERFECTION!!!!!

[@benwalsh8943]

Isn't density also dependent on temperature and barometric pressure? Your description is great for a basic understanding, but in most laboratories they either use a digital density meter or equilibriate the temperature of full pycnometer in a water bath. I would call a pycnometer a very economic way of measuring density but it is not the most accurate. Best is subjective in this case and probably should not be used. I do thank you for a very well produced video and only add comment to contribute and not criticize.

[@citizenscientistsworkshop1948]

Ben Walsh : Thanks for your comment. Pycnometers make it easy to accurately and precisely measure density. The precision is not limited by the technique, but rather by your ability to determine and mass and volume of the instrument. I’m using a very simple and low cost digital scale. If one were to instead use a precision scale that determined mass to say one part in 100,000 then one works need to control for temperature and the buoyant force on the atmosphere. But pycnometers are also used in these applications as well. The precision and accuracy is not limited by the technique, it’s limited by the precision and accuracy of the scale, and the purity of the water used for calibration.

[@esraipekci9467]

Thank you 😊

[@citizenscientistsworkshop1948]

You're welcome 😊

[@manojkumar-re2ye]

Amazed Looking for more videos

[@gabrielawandut9901]

Would it be possible to activate subtitles on occasion? Thank you

[@rokayamouada1474]

So clear thank you

[@gholamrezabonyadi5572]

Perfect. Thanks

[@aalkhasha2023]

ThanQ very much

[@TheJah1985]

OK it perfectly describes how a pycnometer works, but to be really precise, you have to use a way more sensitive scale and must consider the density of the air, that was in the pycnometer as you calibrated it

[@citizenscientistsworkshop1948]

Yes, you are right. But this video was made to support students and citizen scientists and help them to understand the method. I don’t have such accurate equipment in my home lab. Maybe I’ll do a follow up video at a later time. Thanks for commenting.

[@joecooper3073]

This video helped me so much, thank you!

[@citizenscientistsworkshop1948]

I'm so glad to hear it. You made my afternoon.

[@ramaos8542]

You're a life saver

[@ethioupdatedinfo.]

Very helpful!thanks

[@citizenscientistsworkshop1948]

Glad it was helpful!

[@MarkGoren]

This is so good thx so much

[@أسدالصحراء-ر6ف]

Thanks🥰

[@devirajamanththri8003]

Thank you sir

[@madhusudhanreddy1510]

very good explanation

[@user-df5is8jy6n]

thanks for the superb explanation. how accurate this method for porous material such as activated carbon? and what kind of density do I obtain? bulk density, apparent density or true density?

[@AyaZaydan-p8d]

I have a question: When determining the exact volume of the pycnometer, if it is filled with deionized water and contains several air bubbles inside, what impact will this error have on the determination of the mass density of solutions with known concentrations? Will the mass densities be overestimated, underestimated, or does the error have no impact on the determination of the mass density of the solutions? Thank you!

[@citizenscientistsworkshop1948]

The air bubbles will displace water. Therefore the weight of the water used in the calibration will be be too small. This will cause you to underestimate the volume of the flask and therefore overestimate the density of whatever you measure.

[@jerilyncruz5069]

Thank you very much for the video! It really helped me a lot. I do have a question. What if my liquid sample (acetone) is not enough for the pycnometer?

[@citizenscientistsworkshop1948]

Jerilyn Cruz : Interesting question. If you don’t have enough sample to fill your pycnometer you either need more sample or a smaller pycnometer. Now, you could always create a smaller pycnometer by adding a chemically inert solid inside which will reduce the volume and increase the mass. Then recalibrate taking the mass of the instrument to be (glass + solid) and the volume to be the reduced volume, which you measure using distilled water exactly as shown in the video. So, for example, reduce the volume by adding steel BBs until it’s small enough for your sample. Next, recalibrate for the new mass and volume and then thoroughly dry everything to remove all of the distilled water. Then measure the density of your sample. I hope that helps you. Let me know if you have any other questions.

[@abodo12980]

Hi the video is excellent i would like to ask if you have the method in PDF thank you very much A

[@citizenscientistsworkshop1948]

I'm very sorry, but I don't have this in a PDF format.

[@pavan3187]

Please show the calculation part

[@sodoododnyma8864]

I have physics lab tomorrow, prayForMeGuyzz

[@Dylan-d7h]

In my book

[@tomuranokatze6598]

danke vielmals

[@sayad3133]

Hello professor Is it possible to increase the density of mercury?

[@citizenscientistsworkshop1948]

No. Density is an intrinsic property of a substance. It can not be changed.

[@melilianabudiwati2372]

Hi can you teach how to determine what chemical in compound pvc?

[@mixing-pu8fe]

hevac you

[@AlfredIsac]

Man, Great Explanation. But needed one more help please.... How to find the alcohol content in a wine? The issue I'm facing is that because of the presence of unknown particles the density of wine is showing more than 1, the density of water(which is like no alcohol). But surely there is alcohol in the wine. How to solve the issue? To take the density of wine before fermentation instead of water? If so, how to do the calculation?

[@citizenscientistsworkshop1948]

Can you first filter the wine? Or allow the particles to settle out and then decant the liquid?

[@AlfredIsac]

@@citizenscientistsworkshop1948 I've filtered and settled out. By particles I mean invisible particles. The wine is crystal clear with its color. I think what causing the density to be more than 1 is particles that give color, unfermented sugar if any, and nutrients or minerals. Don't know.

[@citizenscientistsworkshop1948]

@@AlfredIsac : You may be right. The density of wort or mash before fermentation is always greater than one. As fermentation progresses the density drops, but it needn't drop below 1.00. If you were expecting the final density to be less that this, then your fermentation may have gotten stuck because they yeast were missing an essential nutrient. I can't tell you why your results are not satisfactory. Did you use a pycnometer or hygrometer to make your measurement?

[@AlfredIsac]

@@citizenscientistsworkshop1948 pycnometer. I used your method. It is working well with disttiled liquids such as vodka. But for wine, I get more than 1 density and hence when I look the ethanol table the comparisons start will alcohol value less than one.

[@citizenscientistsworkshop1948]

@@AlfredIsac the pycnometer always gives you the correct answer if you are using it correctly. If you are getting an answer that you did not expect, and you are sure you are making the measurement correctly, then you need to alter your expectations to be consistent with the value. I don’t know why your wine has the you are measuring, but it’s not a problem with the technique. It must be a property of your wine.

[@kagwangkah2153]

at 3:47 where did the density of the distilled water come from? pls i need an immediate answer. thanks!

[@citizenscientistsworkshop1948]

The gram was DEFINED so that the density of distilled water at 4.0 degrees C would be exactly 1.0000 grams / cm^3.

[@JunkoMay]

is there any standard density for toothpaste ?

[@muhammadim1575]

very informative ...could i measure the density of fat (solid) by this method ?

[@anthonyfeng6180]

and very helpful for a university student ... we can measure the density of fat (solid) by this method

[@WhiteScienceCommunity]

شرح ممتاز

[@sinsrow8975]

It's Trivial to Nitpick. Very Informative nevertheless

[@reza2629]

is it okay to hold the pycno by bare hand? not only glove even covering-tissue? thanks for the video before Sir

[@citizenscientistsworkshop1948]

restu andreza : Yes, under most circumstances. The mass of any fingerprints is far too low to affect the measurements in all but the most sensitive experiments. And any heat transferred through the liquid by handling the glassware is too small to make a measurable difference on the outcome.

[@reza2629]

@@citizenscientistsworkshop1948 thank you for answering Sir. Best regard-

[@kudakwashechenjerai3540]

what method can be used to measure grains

[@jmhannnon]

Interesting, a gadget I was not aware of the name for. Your comments about the grades of steel is a bit confusing. I did a bit of looking and there does not seem to a straight forward relationship between the type of steel and its density. A low carbon steel would be more dense than a high carbon steel because carbon is less dense than iron. A high carbon steel could be considered a higher grade because it is generally stronger. Densities of tool steels are all over the map with each type having specific properties rather than one being a higher or lower grade.

[@citizenscientistsworkshop1948]

Hi Jim, thanks for pointing this out about steel. You're quite right. I appreciate the correction.

[@justmdylan]

In my book au cas où

[@marioperezcortes500]

Good

[@ritusingh6163]

Please aoac table Ka link send kar de..

[@firesurfer]

Ummm, a side note, can the density of gold be faked? That is, using a perfect combination of gold and tungsten to create the equivalent of gold. possibly with hollow spaces inside to match volume? I think in theory, to get a perfect calculation, the particular item would need to be melted down to eliminate spaces.

[@citizenscientistsworkshop1948]

Sure, in principle. But then the expansion coefficient, the reflectivity, the resistivity, thermal conductance and other properties wouldn’t match. There is no way to fake a material’s easy to measure properties at the same time.

[@AJ-uo8tk]

Is it possible to dissolve 1g powder into distilled water and measure the powder's density using this method?

[@citizenscientistsworkshop1948]

No. The density of a dry solid can not be determined from the density a solute into which it is dissolved. The density of the solid depends on the physical arrangement of the molecules in the lattice. That information is lost when the solid dissolves.

[@AJ-uo8tk]

@@citizenscientistsworkshop1948 Thank you for the reply! I believe it is possible with a gas pycnometer but we don't have one in my University unfortunately.

[@Jigoday]

Bhut a66a tha video

[@rangergrade]

Why use this instead of a graduated cylinder? It seems to do basically the same thing:mesure volume

[@firesurfer]

I guess for simplicity's sake. It's a fixed volume making measurements easier.

[@36MSERIAS]

Why are the volume of measured water are way off? And how do you calculate the volume of pycnometer?

[@citizenscientistsworkshop1948]

I can't explain why the volume on the bottle is completely inconsistent with the measured value. You'd have to ask the manufacturer. However, as I show in the video, to calculate the volume to fill the pycnometer with distilled water and weight the instrument. Then you find the weight of the water by subtracting the weight of the instrument dry from the combined weight of the instrument + water. Since distilled water has a known density at room temperature (value given in the video) you divide the mass of the water by the density of the water and find the value of the water, which, since it completely fills the instrument, will also be the volume of the pycnometer. Please watch the video again for all the details.

[@citizenscientistsworkshop1948]

@@angelatampubolon8442 I knew it. The density of distilled water is a well known function of temperature. I took the value of the density of distilled water at the temperature of my laboratory from a table of densities vs temperature.

[@joeschmoe3815]

@@citizenscientistsworkshop1948 You have to order your pycnometers pre calibrated. Then they engrave the volume on the glass wall. Also, do not dab the capillary on the top with paper. This leads to false measurements. Use a syringe needle to scrape away the excess liquid. The dab around the hole with paper. Sources: lab technician. I do this 50 times per week.

[@aSlimyDragon]

Great video, but the massive discrepancy of the pycnometer is bugging me. I feel like you should've poured the full volume of water into a graduated cylinder just to confirm there wasn't something off with the calculations somehow. Because that seems really weird for the printed value to be so wrong. Also, you seem to be using "trivial" to mean "easy". The only non-mathematical definition of trivial has it referring to something that's of little worth or value. Like trivia facts, which are just small, relatively unimportant tidbits about a topic. Might be fun to know, but ultimately not very important.

[@citizenscientistsworkshop1948]

You’re absolutely right. I should have demonstrated the volume error directly. But the electronic scale was calibrated, and the self consistency with the measurements make it clear what the true volume was. Also, thanks for the correction re “trivial.” I have always thought trivial to mean both “trifling” and “ easy to perform.” I’ll keep your point in mind in the future.

[@axelmani9958]

how to determine absolute density of the soil ?

[@jacobcarlos8699]

I don't think you typically use a pycnometer for soil samples but I suppose you could do the same thing shown with the BBs in this video. Just make sure you oven-dry your soil sample first (to remove any moisture content), then fully saturate the soil in the Pycometer to weigh it. You could also lookup ASTM D7263 if you have to access to it, its the Standard Test Methods for Laboratory Determination of Density (Unit Weight) of Soil Specimens.

[@materialgirl4896]

There is a specific type of pynometer for soil

[@methoverlord3976]

density of distilled water is 1 g/ml at 4 degrees celcius not 0

[@anshumanyadav2388]

nice

[@krishnendugiri7077]

How do we calculate pycnometer error???

[@citizenscientistsworkshop1948]

Great question. The simplest way is to repeat density measurements for the same sample material and calculate the observed variance in your answer. Rule of thumb is that you want to do this 30 times to get a good estimate. If you really need the error to be below a certain value then you need the enough data to be able to measure the variance of the variance to confirm whether the instrument is accurate enough for your work. But if this instrument isn’t accurate enough ... you’d be working at a level beyond what I’ve ever required in my research.

[@jrichardjacobs34]

Good video, Shawn. But ... ahem ... an edit problem. The word 'density' on the cube is spelled d-e-n-i-s-t-y. I know, picky picky.

[@citizenscientistsworkshop1948]

Details, details. Oh well, that one slipped by me.

[@jrichardjacobs34]

@@citizenscientistsworkshop1948 -- I know. Rotten devil in the details. Easy fix, or no?

[@citizenscientistsworkshop1948]

J Richard Jacobs : It would be easy to fix the original video if I still had it on my computer. But if I then re-uploaded it all external links to it would be broken. That would cause more harm than good. I’ll investigate the editing tools that exist on KZbin, but I do not think this is easy to fix with the tools there.

[@muetaz_zaydan]

I think a syringe is cheaper specially after finding out these pycnometers can be off by 5 ml

[@MarYouSeeE]

first you suggest that everybody should buy one of this little containers cause their accurate then turns out they are not accurate after all and should calibrate them wouldnt be easy to find a proper container in the first place.

[@citizenscientistsworkshop1948]

Actually, it is TRIVIAL to calibrate the a pycnometer, as I show. Just measure the mass of distilled water that fills the container completely, then divide that mass by the density of distilled water, and you're done. Once the device is properly calibrated you will have a very simple and way to measure densities with great accuracy and precision.

[@tajcnsun8427]

Gak gak gak gak ngerti aku gak ngerti dengan ini semua

[@mohdmirza365]

Wrong process, fill it to the given mark.

[@citizenscientistsworkshop1948]

Mohd Mirza I think you need to watch the video more carefully. There is no mark on the device. This isn’t a volumetric flask. It’s a pycnometer. If you have an objection, please state it clearly enough for me to understand your concerns and to address them properly.

[@bosshai972]

Hello sir I got apparent specific gravity is 1.5 than what would be percentage v/v according to aoac chart. Please help me. I got stuck here.

[@citizenscientistsworkshop1948]

Forgive me, but you haven't given me enough information. I can't tell where the error is from what you've told me.