Lab Equipment: pH measurement with paper and meters [Part 1]

[superpwned80]

algebra, finally something in one of these videos i understand

[pigsnoutman]

Urgh. Calibration.

[INYO121277]

hey a joke :

how to defferentiate acid pH from alkalic ones

drink it.

if tastes sour, that's its acid, if tastes bitter : alakalic

put your finger in it

burns : low pH

sticky : high pH

liabilities : death, scar, and a trip to hospital

[lionman337]

nurd word

[46564364]

Hey Nurdrage, I own a pH meter, but yesterday I immersed it on a 60% nitric acid solution and it doesn't read the pH anymore, what happened? Thank you.

[TechBoywii]

@46564364 the glass electrode probably died, get a new one.

[kirbydude55]

i only understood the litmus paper part because we did this in science class earlier this year <3

[yozgatli66ilker]

Tumbs up if you understand nothing.

Anyways nice vis:P

[tasneem323]

technically yes..... but safety and liability would be an issue

[9mm22c]

this liquid color sample testing seems to have the same concept of just mixing colors to make a new more complex color. but its funny how the outcome is so incohescent.

[jbohbot1]

can you tell us from witch seller you got this ph meter?

[svtcontour]

Great video!

[shawnchen018]

wgy 7.01 recalabration?

[ericon52168]

@shawnchen018 most data was shown in 25degC

when it's 20degC ph7 will become ph7.01

there sohuld bve a list somewhere

[shawnchen018]

@ericon52168 oh ok, thank you.

[lexichronicle2]

thanks, nurd. I have a meter that'll read to 0.001, but I didn't realize it needs storing in salt, so I'll have to do that. one point you could make is that, if your probe won't read correctly in different buffers, you can set it to the pH that's closest to your pH of interest, and that way you'll know you get the important reading more correct.

[kevn123xxx]

nosebleed

[philiprockz]

lol i am doind this cauase i have end of year exam tomorrow and i am revising cause the exam decides my GCSE groups i wanna get top group again i have been top twise. wish me luck

[hhfleury]

Are you a T. A. at UTM by any chance?

[bigupscrew]

How much of each material do you need? In class My group is doing this project and we would like to know how much of alcohol, K-Permaganate, and S-acid is needed for the reaction to occur. Thanks!

[EdwardNavu]

It is a coincidence that I had completed an experiment which involved an pH meter on Friday in the same week you uploaded this video about pH measurements. This is also my first time to use a pH meter.

The objective of the experiment was to measure the dissociation constant of acetic acid and formic acid by preparing buffer solutions of the acids and their corresponding salt of same concentration.

Thank you for providing background information of pH meters.

[superbloody24]

isnt water a ph of 7? why use the 7.1 ph liquid?

[ZyGaming]

You should be a Chemistry teacher.

I mean, you are gonna be the coolest Chemistry teacher ever.

All the students are gonna love you :D

I mean, much better than my Chemistry teachers anyway.

They just read from the textbook and tell us to copy them down..

[NurdRage]

@ZyGaming While the approach of a chemistry teacher depends on the teacher, the subject itself is 99% boring with only 1% cool stuff. I might look cool on youtube because i show mostly the 1% cool stuff. But to get to that 1%, you have to first slog through the 99%

Is your teacher *actually* boring? or is the stuff they're teaching boring? ;)

[ZyGaming]

@NurdRage You are right.

I actually love Chemistry myself, sometimes I'd all of a sudden looking for some random stuff about Chemistry on google...mostly that 1% cool stuff though, haha.

But well.. they aren't boring, no offense to them but they really can't teach..

and all my classmates think the same ^^

I do alot of subjects, Chemistry is the only one that I don't revise for..

I gotta LEARN it by myself at home reading the book, cause the teachers are so bad at explaining it's unbelieveable xD

[mewrox99]

@NurdRage

lol the 'boring' parts of chemistry I find the most interesting

[andersvj]

@NurdRage I can't belive you would say that it's 99% boring. I like the experiments but the theory is very interesting aswell.

[hhfleury]

@NurdRage After finishing first year chemistry at U of T, I couldn't agree more with that comment.

[dukilaki]

@NurdRage again you should be a teacher

[INYO121277]

@ZyGaming man, it's a 99% boring one(this vid). but it's great to watch

[habbopassload]

There's no rating anymore

It's only Thumbs up ;D

[martha2ful]

Is there is any type of acid, etc. that would be able to completely dissolve a vegetable plant upon contact, or within say a matter of minutes?

A client of my landscaping company wants to have a large container filled with a substance that she can throw her unwanted vegetable plants, leaves, etc. into and have them completely dissolve in the shortest amount of time possible, preferably on contact. Any advice, or suggestions would be greatly appreciated.

Thank you.

[NurdRage]

@martha2ful technically yes..... but safety and liability would be an issue, any substance that powerful would also dissolve human flesh very effectively. Even a small splash out when you drop something would be a horrific.

I recommend just a mulcher or similar mechanical approach to grind the matter into a paste and then flush it or compost it.

[SirezX]

@NurdRage

I came here from your fluorescence thermochromism video (which was totally awesome btw) cause you said it would probably bore us out of our minds...in fact I find this most informative...i'm not sure what I would actually put this into practice with but still...none the less...very informative...I have measured PH before but only for watering specific plants and stuff that prefer certain PH levels...haha...

[biowerks]

@martha2ful Is this comment a joke? I mean really...

[SkorpStriker]

@martha2ful That sounds sketchy...

[MrBulletproof87]

subs?

[ducati929]

Dissolved CO2 in the DI water likely gave you the low pH

[NurdRage]

@ducati929 huh?

[ducati929]

@NurdRage Disregard this one, wasn't paying adequate attention to video - missed the pH 7 bath was a buffer solution, was thinking it was DI water, which would likely have dissolved CO2 and thus a lower pH, explaining the "overcorrection" I perceived that wasn't actually there

[NurdRage]

@ducati929 ah gotcha

[1zacster]

Aren't there ones with a metal rod and both the electrodes on the tip that measures the ph? And to buy all this stuff how much money do you make? You don't have to be specific or youdont have to tell me if you dot want to

[NurdRage]

@1zacster Some cost more, some cost less, but on average it costs $100 per vid

[Barnekkid]

Thanks Nurdrage, that was a very interesting video.

[4states1universe]

Can you make a video on ammonium sulfide. hehe..

[glenwoofit]

Very interesting, As always.......

[dude20148]

hey small question are u a chemistry teacher u have so many cool equipment

[NurdRage]

@dude20148 Research scientist

[samn100]

@NurdRage What do u research

[TheElemental5]

I was using this last week! lol

didnt expect you to show this

[Glockffs]

Ah, using Excel to give you a compensation formula using a trendline, that's a great idea.

[Fermions83]

i have used those before and never actually knew how they worked, thanks

[jbohbot1]

dear nurdrage, i have a question about lead acid batteries. is it possible to purify the sulfuric acid in the battery by hooking up the two terminals of the battery to an electrical output in my house? by the way, im talking about a 7v lead acid batter not a car battery.

[NurdRage]

@jbohbot1

O_o

DON'T PLAY WITH MAINS VOLTAGE!

Besides, it wouldn't work anyway, the excessive voltage will likely cause the plates to disintegrate and fill your acid with particles of lead and lead dioxide.

[jbohbot1]

@NurdRage

:( what do you mean by "DON'T PLAY WITH MAINS VOLTAGE!"?? thanks for replying.

[ducati929]

Not to mention the fact it's AC current.

[NurdRage]

@ducati929 what?

[ducati929]

@NurdRage tried to reply to the comment posted by the person wanting to run electrolysis through his wall outlet. Not sure why it ended up as a stand alone post

[The0Burger0King]

We have some USB pH readers in the chem lab at my school. I think they are expensive ones though.

[Sillybillydilly]

That porous plug is called the reference junction, that creates an electrical connection, but only a slow diffusion connection; the reference electrode is on the inside; usually Ag wire/ satd. AgCl, or Ag/AgCl in satd. KCl ([Cl] affects [Ag] through Ksp common ion). Hg/Hg2Cl2 used to be the best reference electrode, but Hg sucks for safety/health. Hence Ag, but Ag is is affected by light. I would prefer Cu complexer precips to Ag and Hg, don't know why they are not used. Cu is still noble enough

[NurdRage]

@Sillybillydilly You still need to immerse the electrode up to that part in order to obtain an accurate and stable pH reading.

Anyway, you are right that exposed part is the plug but it is still part of whole reference electrode assembly, and you need the whole thing behind it in order for it to work.

When you point to a car you usually only see the car body and not the engine, but the whole thing is needed and it isn't wrong to call what you're pointing the car, rather than the car body.

[NurdRage]

@Sillybillydilly As for the construction of the reference electrode, you're absolutely right but i felt it would clutter the video too much. I left it out since the design didn't really change how to use it.

As for mercury, i think that's no longer used, i could be wrong through, i think silver is still a major component of most references although i'm unsure.

[Cla0016]

Back in highschool i remember using a ph testing rod that attached to a ti-84 calculator.

[iwan0t0smith]

You can't say you don't have red litmus paper, You just made some by dipping the blue paper in the acid,

I think it would be good if you where to show that effect in upcoming vids

[NurdRage]

@iwan0t0smith technically you're right, but practically it's not the best way of going about it. The acid used was quite a bit and a lot of it sticks to the paper. If then i dip the paper into something only weakly basic it wouldn't change color because the acid sticking the paper would overpower it. Red litmus paper is best made by using *just enough* acid to convert it and nothing more. So it would be sensitive to weakly basic solutions.

I didn't have such paper. thus the line in the video.

[iwan0t0smith]

@NurdRage True but I still think id would be an interesting demonstration of how litmus paper works.

I really like your vids btw

[NurdRage]

@iwan0t0smith gotcha, i'll think about it :)

[bobshinowski]

I have a classmate who sounds just like this voice

[hkparker]

Its great to see some videos on equipment and technique!

[magicbuskey]

Thank you for another fine video!

[MonsterVSNos]

wow fucking alters his voice so no one can no who he is... nurds are fucking gay and i bully them everyday

[WrCmdSaul]

@MonsterVSNos ofcourse you do, you have to compensate for having a small dick.

[FFXPWNS]

@WrCmdSaul HAAAAAA, you took my comment

[FFXPWNS]

@MonsterVSNos wow, you sound like a loser

[ytmachx]

Great video demonstration!

[nabnabking]

Im surprised you didnt go into what buffer solutions are, the whol acid and conjugate base or base with conjugate acid. Is the reason you dont get buffers at ph 7 due to this?or can you get them and i havent seen them.

[alexdenton02]

@Nurdrage I hardly ever post, but I have been following you for about 2/3 months now and just want to say thank you very much for your videos. I'm currently a first year student in chem at my local junior college, and I watch your videos to peak my interest in chem. And I must say it works very well^^ I would say this video isn't as "cool" in the "light chit on fire" ones, but nonetheless, I enjoy it very much because I to one day want to work in a lab. So many thanks again =)

[NurdRage]

@alexdenton02 thanks!

i do agree, this is one of my more epically boring videos, but we have to slog through this to get to some better stuff. Driving fast cars might be fun, be we gotta build the car first.

Thanks for understanding :)

[alexdenton02]

@NurdRage Well to be completely honest, I would appreciate more of these videos, because knowledge like this helps anyone who wishes to be lab bound. And unfortunately, stuff like this is usually learned when you have to finally do it. Unless your fortunate enough to have someone like you explaining it to us^^

[dannynguyen123]

this is the best video because just today we started learning about this units

pH measurement and watching this video made this unit just a whole lot easier :D

thank you nerd rage <3

[Skullatoran]

I remember using Ph paper in science for the acids and bases labs, it was pretty cool

[sorathelight223]

ooo my chem class is doing stuff with acids and bases :O gogo reg chem for high school XD

[dragonridley]

Hmm, I guess my litmus paper is weird. It's halfway between the red and blue litmus paper you mentioned.

Your talk on calibrating the meters reminded me of one meter that was WAY of in its calculations.

[C6R1S]

the glass electrodes meters are pretty accurate once adjusted to the 7.0 buffer solution. the reason they get off in between test is the distilled water. no matter how much you try you cant get all the water off and this throws the pH up for acid solutions because it dilutes them and the down for base solution. I have found if you test with a second vial after the first one washes the water off it is more accurate.

[dudomaniac]

@C6R1S That is why pH calibration solutions aren't just an acid in water, they are buffered solutions. By dissolving an acid and one of its salts in the same solution, the pH stays the same even after diluting, adding a little strong acid or a little base to the solution.

[C6R1S]

@dudomaniac I guess it was some cheap buffer solution i was using then, plus I mainly use it to test the pH of water for my plants ;-P

[NurdRage]

@C6R1S if it's for plants then go for it. Plants are more forgiving of pH differences (to a point though...) than some chemical reactions.

I'm just being anal because I used to do analytical chemistry, maximizing accuracy and precision was an epic quest in itself.

But yeah for plants, go for it, around pH 7 is alright. But still use good buffer solutions. :)

[NurdRage]

@C6R1S Adjusting to a particular buffer like 7 should be done with some knowledge of whatever chemistry you're doing, if you're working near 7 in your experiment then go for it. But if you're working near 4 then get a pH 4 buffer and calibrate to that. Likewise for 10. This is to minimize any slope or proportional errors in the electrode or the meter.

Picking a calibration point arbitrarily is not a good idea.

[BrotherBloat]

as always - top grade stuff! thanks :)

[brainanator]

This isn't as cool and burning stuff and what not, now you're just reminding me of college chem lab :p

[NurdRage]

@brainanator we have to slog through this in order to get to some more interesting stuff.

(psst... we're going to make ammonium nitrate)

[almasapparition]

Thanks for the tip about not immersing the indicator strip into the solution. You make a good point I hadn't thought of.

[wowggscrub]

can you make your own buffer solutions?

[Rototill27]

@wowggscrub

Yes you can. A buffer solution is solution of an acid and it's salt. (i.e acetic acid & sodium acetate). Of course, you have to sit down and figure out the stoichiometry but it can be done easily. Ultimately, it is just easier, cheaper and more time efficient to purchase the analytical grade stuff. Buffer solutions resist drastic changes in pH. Your blood is a buffer solution. Your enzymes would be toast without it.

[NurdRage]

@wowggscrub yeah.... but there are a lot of factors you have to consider like ionic strength, dissolved gases, purity of chemicals, stability, ion activity and a host of other issues in order to maintain a predictable pH. It can be done, but not worth it.

Also, how do you tell if there's a mistake? use the mis-adjusted pH meter? :)

Most companies that sell pH meters also sell the solutions, so if you're willing to go that far to get a meter, it's not much harder to get the solution.

[pyrocrazyUSA]

At 1:24 i couldn't understand what you said the price was.

[NurdRage]

@pyrocrazyUSA $40

[DaChaosSeeker]

whertes the explosions?

[jagjagin]

very nice video, never realized how much instruments can be used to indicate pH levels.

[nikulp68]

what about tea!

[trailkeeper]

Knowing the pH of foods we eat is good. Some say having an acidic body is bad for health unless you're trying to eliminate germs.

[carljuve]

why did u wash the electrode in dilute water?

[Y0pbe]

The red cabbage juice is also a good pH indicator.

[digdugdiggy]

dip the Blue paper NOT into the base

Thats how my chemistry I teacher taught us. you think its B - B but its not

[sealhunter5]

Great info on the buffering solutions.

[RoNM214]

How about using methyl orange and phenolphthalein?

[NurdRage]

@RoNM214 go for it

[AfricanMadman]

You can also use a egg to test acidity in liquids.... But it takes longer though...

[gavincfc]

@AfricanMadman really?how:-D

[AfricanMadman]

@gavincfc You take the egg (uncooked) and place it in the solution....

Depending on the acid in the solution, you can tell it's strength by how fast the shell looses it's stability...

[SuperRichard37]

Thank you! I couldent rember for the longest time what color was what on my red and blue litmus paper. Keep making great videos! Alot of us are learning from them. Thanks again -SuperRichard37

[NurdRage]

@SuperRichard37 sure will, thanks for watching :)

[MacroVamp]

@SuperRichard37 Why not just try to dip it in something you already know? Like, dipping it in ammonia

[neoliner1234123]

xD like anyone would care that u are first... anyway nice vid ^^

[PyroFreakDJ]

@neoliner1234123 Uhm, I care. These Frist comments keep me alive.

[gavincfc]

@PyroFreakDJ lol