Questions tagged [equipment]

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

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28 views

Reason for rounded fitting at the top end of Allihn Condenser

I am purchasing an essential oil distillation setup. The Allihn Condenser at the top end, and the attached glassware, are rounded. It is supposedly 24/40. I have never seen this. If one of them broke, ...
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1answer
84 views

Removing PTFE marks on glass bottles after using magnetic stir bars

I am using magnetic stir bars to agitate solutions for 4 weeks at a time. I have noticed at the bottom of the glass bottles that white marks have accumulated where the stir bar spins. Even with ...
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5answers
48k 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 ...
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1answer
43 views

Type of equipment to measure exact amounts of liquid

I have to sample $\pu{10mL}$ of liquid hundreds of times a day at work. We use a $\pu{10mL}$ syringe to do so, but it takes a lot of time as they often allow more than $\pu{10mL}$ to be drawn in (i.e....
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1k views

Benefits of a Buchner funnel w/ a fritted disc instead of Quantitative Filter Paper Circles

I was wondering if someone could enlighten me on some example us cases where one would be better of using a Buchner funnel with a fritted disc (example), as opposed to a Buchner "style" filter (...
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1answer
89 views

Pipette Pump durability?

I want to ask, according to your experience, in terms of durability and longevity of the tools, which one of these types of pipette pumps is better? and the reason why? 1) Tri-valve Pipette Bulb 2) ...
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3answers
7k views

Why is the outermost part of the Bunsen burner flame not the 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 ...
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1answer
2k views

What is the scientific term to describe the operation of a bong?

What is the scientific term for the separation of dust particles from air by suction through a specialized flask in a way similar to the operation of a bong? The thing that led me to this was a ...
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4answers
80 views

Will ground glass joints relieve pressure non-catastrophically?

I need to heat a fluid for seven days at a time. The fluid goes in round bottom flask that is suspended in a water bath. The test fluid will decompose and generate a small amount of gas over time. ...
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2answers
559 views

What equipment to use to make liquid oxygen?

I'd like to do some experiments with liquid oxygen but as a first step I'll have to make some. Unfortunately I don't have any experience designing cryogenic experiments. I'm thinking I'll cool gaseous ...
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36 views

BOD5 respirometric method

I operate in a wastewater treatment plant laboratory and I use respirometric method for BOD5 measurement (hach direct plus). Recently I am obtaining high value for BOD (biological oxygen demand) for ...
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23 views

Permanent storage container with electrode for electroplating

I'm not a chemist at all but I am looking for a specific type of container which I'm sure must exist but I don't know it's name. We want to store non-toxic (non-cyanide) gold solution for ...
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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 ...
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3answers
2k views

Why did my glass pot explode when I boiled sugar in it and added cold milk?

I decided to try some cooking with sugar and put a glass bowl on the flame with half a cup of sugar in it and some water. After bubbles appeared I stirred the sugar for about a minute and then I ...
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1answer
283 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 ...
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1answer
81 views

Order of internal pressure resistance to expect from laboratory glassware?

I have a need to use more pressure differential than can be afforded by vacuum vs atmospheric pressure alone, and so I've come to consider using pressurised laboratory glassware for part of my setup. ...
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37 views

NaOH vs Polypropylene

This source lists polypropylene as suitable for use with NaOH. However, this paper seems to demonstrate that NaOH slowly degrades polypropylene (even at fairly moderate temperatures). Does anyone ...
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1answer
129 views

Labware to handle hot aqueous NaOH

This question regarding appropriate handling of hot concentrated aqueous $\ce{NaOH}$ - with particular concern for avoiding dissolution of borosilicate glassware and contamination of the $\ce{NaOH}$ ...
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55 views

Highly concentrated NaOH solution at high temperature vs borosilicate glassware and cellulose?

I've read here on stack-exchange that NaOH will react with glass through the following reaction: 4 NaOH + SiO2 ⤑ Na4SiO4 + 2 H2O I would like to briefly heat a highly concentrated NaOH solution to ...
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1answer
120 views

What kind of metal drums are used to store Hydrochloric Acid?

I would expect Hydrochloric Acid to be stored exclusively in glass or plastic containers, but I was surprised to find Honeywell offers it for sale in 30Kg metal drums (Link). I think Hydrochloric ...
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0answers
35 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 ...
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2answers
141 views

Glass joint stuck in flask

I am doing distillation using system of glassware including a flask and a glass joint. Recently I've faced a problem: the glass joint stuck in the flask. I tried to remove it but it broke and hurted ...
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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 ...
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2answers
7k 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?
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1answer
41 views

Can I safely use a separatory funnel to extract the precipitate from a solution?

Can a separatory funnel be used to collect a precipitate, or would that risk clogging the stopcock on it? I'd like to recoup the precipitate for filtering without passing the entire solution through ...
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1answer
51 views

What are the components of a labware setup for short-path distillation?

I've recently become interested in short-path distillation and have found that most kits are in the thousands of dollars. So I thought that I would compile the labware myself. I understand the theory ...
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2answers
1k 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 ...
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37 views

Can we use potassium iodide as pH meter electrode storage solution.? If not then why?

If KCl is not available can KI be used to store pH probe meters? Both are potassium salts.
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2answers
686 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/...
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0answers
67 views

An unknown glassware piece from our cupboard

We have multiple of these. It is a small glass funnel with splits into 3 spouts from it. Now, we are thinking it might be similar to a cow receiver, however, I have never seen one this small or ...
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35 views

Unknown possibly handmade glassware- description in information below

Okay, Another random item from the cupboard (unknown users or discipline of life sciences unknown) could be anything up to 40 years old.... This appears to be a 2 neck quickfit adapter (B19 and B14) ...
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55 views

Unknown glassware please help, vshaped with a small bulb on one side, hollow but narrow to both sides!

Looking to try an identify some glassware we have found in a cupboard. This is just the start of it... 1 item here, v-shaped, small bulb but hollow, narrow entrance and exit...
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1answer
862 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 ...
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1answer
391 views

Devitrification vs glass transition temperature

This graph comes from a so-called "differential thermal analysis". It is studying the effects of temperature on glass. I don't understand what the difference between "glass transition" and "...
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22 views

Why a Differential Scanning Calorimeter (DSC), to measure thermodynamic parameters, has problems?

I want to use a Differential Scanning Calorimeter (DSC) to determine when my protein unfolds as you increase the temperature in a DSC machine. The machine is pressurised (to 3A) during the run, so ...
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2answers
220 views

Will borosilicate glass absorb 808nm laser light?

Will borosilicate glass absorb 808nm laser light? If it instead refracts, then what is the refractive index? Also, will borosilicate reflect lower frequencies of light like those used in non contact ...
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1answer
357 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?
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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 ...
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0answers
234 views

Why molten lithium burns through the glass but sodium not?

It's well-known in laboratory practice that one shouldn't melt lithium in a glass equipment and there isn't such rule about other alkali metals. You may damage the glass with sodium but lithium will ...
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1answer
817 views

Rule of thumb of how much vacuum does lab glass stand?

Sometimes I have to apply vacuum to all kind of different borosilicate glass equipment like: round bottom flasks liebig condensers fractional distillation apparatus spiral condensers chromatography ...
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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 ...
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1answer
2k views

What's this glassware?

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

Name of this glassware?

Could you tell me the name of this glassware? I found it in the laboratory with a label that says "container of stoichiometry", but I have not found more information about it, especially about the ...
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1answer
76 views

Difference in application between Standard Type Bulb Pipette Filler and Universal Type?

I want to ask what is the difference in terms of application between the HHH (Heinz Herenz Hamburg) Bulb Pipette Filler Standard Type (1081801) and the HHH Bulb Pipette Filler Universal Type (1081802)?...
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1answer
35 views

Standard for Chemistry Supplies [closed]

In searching for chemistry kits it often leads to stuff like this: I have seen some nicer "boxed sets" for the ~$500 range, but I don't think this is really ideal. This one looks a little nicer. I am ...
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3answers
9k 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 ...
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3answers
8k views

How to judge accuracy and precision of measurement devices?

I am unsure about the accuracy and/or precision of measuring instruments. For example, if we have a graduated cylinder, a pipette and a beaker, how and why can we assert them that they can be used ...
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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?
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155 views

How can I get this glass stopper out? Need troubleshooting!

I placed a glass stopper in a $\pu{100 mL}$ round bottom flask while my solution was still warm and let it cool overnight. Now I think I created a vacuum seal and I can’t force the stopper out to ...
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1answer
6k views

Purpose of an Iodine Flask

Is there any specific reason why Iodine Flasks are used instead of Erlenmeyer Flasks when doing Iodine Determination tests? Iodine Flasks are quite expensive when compared to Erlenmeyer Flasks. Does ...