Questions tagged [equipment]

Questions regarding the equipment used in labs (such as flasks, tubes etc.), their operation and maintenance.

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38
votes
5answers
44k views

Choosing the right condenser

What are the advantages and disadvantages of the various types of condensers commonly found in the laboratory? Obviously more intricate pieces of glassware are more costly but assuming they are all ...
27
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3answers
2k views

What benefits do higher-rated NMR tubes provide?

You can buy NMR tubes in a huge variety of qualities, with an equally huge difference in price between the cheapest and the most expensive NMR tubes. They are usually rated for a specific spectrometer ...
23
votes
11answers
3k views

Help me identify this glassware!

I'm a freshly graduated physics and math teacher moved into a small school from the late 1920s. The equipment here is old and confusing, at the very least. I have found many things which I have ...
22
votes
4answers
40k views

what kind of suspension liquid should be used with ferrofluid (so it does not stain the glass)

Please take a look at the following video: I am working on a new project, and I need to find whats the best liquid to hold ferrofluid inside the glass (or maybe even plastic) container, so that ...
20
votes
1answer
2k views

Does anyone know what this piece of glassware is?

I recently found this piece of lab glass with a jacket and spout. It says eubilicmeter but I cannot find any information about it online and I do not know what it is supposed to do. It is hollow in ...
18
votes
2answers
2k views

What is the “blue spirit” (or “red spirit”) in mercury-free thermometers?

I surmise it's some kind of alcohol, but is there a standard chemical used for these? One of them just exploded in my students' lab! It was the kind with blue fluid in it.
17
votes
5answers
3k views

Why isn't pressure filtration popular compared to vacuum filtration?

I want to build a DIY vacuum filtration apparatus with a bike pump but it's very difficult to find one the could be easily converted into a vacuum pump. This prompted an idea to simply build a reverse ...
17
votes
1answer
2k views

What's this glassware?

Can anybody tell me what this glassware with a stem, bulb and long tube is?
17
votes
1answer
1k views

Conventional heating compared to microwave heating of chemical reactions

In order to try to increase yield of my cross-metathesis, it was suggested to carry out the reaction in the microwave (a lab microwave, not a kitchen microwave). The rationale for this was that ...
17
votes
1answer
675 views

Unknown glassware

I recently found a piece of older glassware in our lab and nobody seems to know what it is. It appears to be some sort of condenser; however, it does not have both the in and out little notches on it. ...
17
votes
2answers
1k views

Safety in handling of concentrated ammonium fluoride

I recently saw a protocol for extracting organic materials that are bound in the silica matrix formed by diatoms. The extraction protocol used 10 molar ammonium fluoride ($\ce{NH4F}$). I briefly ...
16
votes
2answers
2k views

pH probe bulb - what is happening within the glass?

I am trying to understand how the glass bulb of a pH electrode of a pH meter works - the glass bulb itself. Not the reference electrode or the rest of the electrode (HCl, Ag/AgCl wire, etc...), the ...
15
votes
2answers
940 views

What is this Lab equipment?

I want to know the name of this equipment with a sealed graduated tube and the purpose it's being used. I went through all the results of Google, but I was unable to find this exact equipment. I ...
15
votes
2answers
1k views

Are PTFE stir bars resistant to all lab solvents?

It seems like glass-coated stir bars are a specialty item. Standard stir bars are coated in PTFE. Is PTFE resistant to all typical lab solvents? Or is there a reference to check to ensure it is ...
14
votes
2answers
2k views

Why does KCl come in amber coloured bottles?

I remember from school that photosensitive chemicals are kept in amber coloured bottles. Is KCl photosensitive? I read up the impurities list on the bottle and it says that it may have bromides too? ...
13
votes
3answers
2k views

What are the plastic connectors called (for glassware)?

I can't remember for the life of me, and google isn't making it easy. e.g. the things labeled 24/40 etc., as in this picture:
12
votes
5answers
16k views

How to stop goggles from fogging?

I wear corrective eyeglasses, and because of this, I frequently experience problems with fogging when I wear safety goggles. How can I prevent or reduce fogging? The safety goggles I use are the ...
12
votes
3answers
13k views

Cleaning a round-bottom flask, especially after distillation

I was wondering, how can I clean my RBF after doing a distillation? Cleaning it with a simple pipe-cleaner or similar cleaner is a headache, due to the roundness of the flask. Is there a more ...
12
votes
3answers
7k views

How to remove a stuck stopper from a flask?

How do I remove a stopper that has been stuck in the neck of a 100 mL round bottom flask since I forgot to wipe the neck of the flask. A salt was formed in the 100 mL flask and the stopper ...
12
votes
1answer
97 views

High temperature bath chemicals

I have an electric mantle that I want to bathe reaction vessels at temperatures up to $\mathrm{750^{\circ}C}$. Obviously that rules out oils. What substances are used as bath media at such ...
11
votes
1answer
856 views

How is polarization of light measured?

Chiral molecules are classified as dextrorotatory (+) or levorotatory (-) depending on whether they rotate plane-polarized light (ppl) to the right or left. My question is, how is such a measurement ...
10
votes
3answers
34k views

Water flow in condenser

How should the water flow in your condenser? From the flask to the top of the condenser, or from the top of the condenser back to the flask? I could imagine both: flask to top will fill the entire ...
10
votes
2answers
3k views

How to quickly cool a test tube without cracking it?

Is there a way to safely cool a heated test tube quickly without cracking it due to sudden thermal stress in the glass? One thing that I tried was blowing on it, cooling it in slightly lukewarm water ...
10
votes
2answers
566 views

Use of pipette during experiments for determination of oxygen by Winkler's method

We were performing estimation of $\ce{O2}$ by Winkler's method and we were told by the instructor that while adding $\ce{MnSO4}$ and $\ce{NaOH}$ / $\ce{KI}$ the pipette tip should be well below the ...
10
votes
3answers
1k views

What angle limits should apply to Graham condensers?

I have seen Graham condensers set at an angle (perhaps as low as 30 degrees from horizontal). I guessed this wouldn't be a problem because siphoning would clear the condensate. But I recently saw an ...
9
votes
2answers
5k views

What is the accuracy of medical syringes?

I am interested in both low and high volume syringes.
9
votes
3answers
601 views

MacGyvering a sealed tube

Is it possible (advisable?) to make a sealed tube by melting and twisting the end of a borosilicate test tube? One issue that I can think of is that the pressure might be too high if I then proceed to ...
9
votes
1answer
1k views

Why are Erlenmeyer flasks shaped the way they are?

The title says it all. We could conceive a good number of other possibilities. Why did Erlenmeyer arrive at this design?
9
votes
3answers
6k views

Bunsen burner and hottest region

Why is the blue flame the hottest on a Bunsen burner? I thought the outermost part of the flame must be the hottest region because of complete combustion of gases taking place there.Where am I ...
9
votes
1answer
635 views

Why does a glass tube show white bands after being heated with a torch?

When I use a torch to split a glass tube, there's always a hazy white band which appears. Does anyone know what the cause of this is? It was a hydrogen-oxygen torch. The glass is fused quartz glass, ...
9
votes
4answers
711 views

How much does the quality of glassware matter, really?

Discussing about the pros and cons of glassware from different manufacturers for chemistry experiments easily becomes a heated debate. Well, that's how it seems if you read the chemistry related blogs,...
8
votes
1answer
4k views

How is aqua regia stored?

How is aqua regia stored as it dissolves all metals?
8
votes
2answers
672 views

400–430 degrees Celsius heated bath

I want to perform a reaction which needs the temperature to be maintained between 400–430 °C. Since it's the only practical solution, I opted for a heated bath. I'm looking for a hydrocarbon fraction/...
8
votes
1answer
179 views

Why is there a bulge at the top of my volumetric flask?

Sometimes volumetric flasks are designed with a bulge in the neck right below the stopper opening. What is the design intent of that bulge?
8
votes
0answers
771 views

What drives the cost of Raman spectroscopy? [closed]

Raman spectroscopy setups are quite expensive- \$10-\$30k seems pretty common. The spectrometer, the probe/fiber cable, and the laser are typically each $3k+. The spectrometer could potentially be ...
7
votes
1answer
325 views

What are these upside-down glass egg-shaped containers for?

I took this picture from a chemical vendor, but I've seen these things many times already. How are they called and why are they upside-down?
7
votes
1answer
142 views

Gold Plating on Glass?

I am considering labware options to handle NaOH solutions at ~150°C. One appealing idea would be to coat my current glassware with gold. I've read different sources mentioning the possibility without ...
7
votes
1answer
5k views

How many decimal places should a volume measurement in a beaker include?

I have a beaker which goes up in $0.5~\mathrm{mL}$ increments and my teacher told me that my measurement $(15.50~\mathrm{mL})$ was incorrect, and instead the answer was $15.5~\mathrm{mL}$. I don't ...
7
votes
1answer
1k views

Ductless fume hood for acetone?

Administration on my campus has become worried about the lack of a fume hood when using acetone in the 3D Print Club. I'm helping in the process of picking one out. They do acetone vapor smoothing on ...
7
votes
1answer
958 views

Vacuum distillation apparatus selection and configuration

I want to assemble a "hobbyist-level" vacuum distillation apparatus for extracting small volumes of "typical" solvents (e.g., water, alcohols, ketones, diols). I already have standard lab glassware ...
6
votes
2answers
6k views

Why is a volumetric flask shaped the way it is?

A volumetric flask does not look like an Erlenmeyer flask, but has more of a pear shape. Is it just to distinguish more easily between them while they are on the shelf?
6
votes
3answers
25k views

What's the difference between pipettes calibrated “TD”, “TC”, “Blow-out” and related terms?

I've never blown-out the last drop of any glass pipette I've ever used during my undergraduate studies. Recently I re-read some notes I had lying around in order to prepare a class I had to give to a ...
6
votes
1answer
182 views

Types of argon gas regulator? [closed]

I have a high pressure bottle of argon gas (99.98 %) that I need to use in an experiment. The problem is that the regulator I have is a generic type that is seemingly optimized for high flow rates (...
6
votes
0answers
34 views

Identifying Name/Purpose of piece of ellipsoid glassware with internal tube?

I recently went to a market in Southern France and found this little piece of equipment for sale along with a whole bunch of other chemistry things. the guy had no idea what it was for or where he'd ...
6
votes
0answers
430 views

What is the fabric in heating mantles made of?

An ordinary lab heating mantle often has a white fabric coating for the flask compartment, which looks like an inorganic fiber: Image source I'm pretty sure that for some time in the past ...
5
votes
1answer
338 views

What is this piece of glassware called?

Here's an image: The left side is designed to be fitted into a beaker, and it captures gas evolved during a reaction. The right side can be filled with a liquid to then react with that gas. We use ...
5
votes
1answer
284 views

A chamber to control concentration of a vapor: Is there a name for this equipment?

Mechanical engineer here so please excuse me if my question seems dumb to you! I want to have a chamber $(\approx 40 \times 30 \times \pu{30 cm})$ to control concentration $(\pu{ppm})$ of a flammable ...
5
votes
2answers
77 views

Kipp's apparatus with powders

A Kipp's apparatus has three distinct bulbs. The topmost one contains a liquid and a tube to the bottommost one. The middle one contains a solid to react with the liquid. This is very understandable ...
5
votes
3answers
225 views

What are good lubricants for Bunsen burners?

We've been running into a lot of problems the last several years with our laboratory Bunsen burners becoming jammed and/or corroded. I've just come to find out that our lab tech has been lubricating ...
5
votes
1answer
391 views

Can I get an accurate temperature reading from a flask with a built-in thermometer well?

I recently purchased a flask with a built in thermometer well, but I have discovered that simply setting a rod thermometer in the well does not produce a very accurate reading. I was wondering if ...