Questions tagged [equipment]

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

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Why do Büchner funnels have no glaze on the top rim?

I have a question about Büchner funnels (just out of pure curiosity). The funnels I have seen have no glaze on the top rim. Actually, the question is why the top end is not glazed. Does it have any ...
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3 votes
0 answers
24 views

Which vessel materials are compatable with magnetic stirrers?

I am shopping for some metal pans and beakers for use on my magnetic stirring hotplate. I do not want to block the magnetic coupling of the stir bar. The question is which common alloys are compatible?...
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  • 207
2 votes
0 answers
43 views

Connect glass tubes to a graham condenser

I am currently making a syphon coffee maker such as this one: However, I find that all the silicon tubing used on this image between the condenser and the boiling flask / between the condenser and ...
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0 votes
1 answer
58 views

Experimental setup

I would like to know your opinion regarding the setup of a system for oxygen purging with nitrogen. Before ordering the necessary materials, I'd like to be sure if this setup is feasible or if it can ...
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3 votes
1 answer
126 views

How should you report measurements and uncertainty for a measuring cylinder with 0.5 mL graduations?

I understand that a common convention is to report the uncertainty of an analogue instrument as plus or minus half of the smallest scale division. By this logic, a measuring cylinder with $\pu{0.5 mL}$...
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0 answers
35 views

What material should my evaporation dishes be made of to combat static charge buildup?

I have great difficulties moving very fine powders from a drying dish (glass) into small plastic containers using a metallic spatula due static charging. I have to scratch a lot inside the glass ...
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  • 239
0 votes
0 answers
37 views

Glass fritted filter

Today I soaked my glass fritted filter with sulfuric acid 95% diluted 3 times. After many hours I wanted to check it but I found that the glass layer turned to grey or light blue color! I want to know ...
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2 votes
0 answers
40 views

Best bet for separating fused glassware

I have a sintered glass funnel stuck in a flask with a 24/40 ground glass joint. I regularly used this glassware to process very dilute solutions of uncured photopolymer resin dissolved in ethanol. ...
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  • 1,092
0 votes
0 answers
36 views

Waste management of hazardous solvents

How should one safely dispose of chemicals like dichloromethane, toluene or acetone that were mixed with water? Is the water contaminated to a degree that it needs also treatment? For example ...
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6 votes
2 answers
2k views

Which is a more accurate scale for a chemistry high school lab - a triple beam balance or a digital balance and why?

I would like to ask the experts of this chemistry community their opinions on which balance is more accurate and effective to use in a high school chemistry lab- a triple beam balance or a digital ...
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  • 637
5 votes
2 answers
473 views

Is there a simple way to distinguish grades of purity for copper metal?

Is there a simple way to distinguish different grades of fine copper purity (on a trace metal basis) that can be carried out in a small lab? Specifically, I would like to be able to differentiate 4N, ...
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  • 889
0 votes
2 answers
82 views

Can stainless steel be electrically insulated with (oven-dried) Sodium Silicate Solution?

Can I electrically insulate stainless steel by painting Sodium Silicate solution on it and heating it to 200C for 30min or so? The solution should be conductive, and I've been told (to be verified) ...
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1 vote
1 answer
62 views

Will Sodium Polyacrylate (SAP) absorb the gas from liquid ammonia?

I'm considering using sodium polyacrylate grains to absorb spills of a relatively strong Ammonium Hydroxide solution. Will the SAP (super absorbent polymer) only absorb the water, and in effect make ...
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1 vote
1 answer
39 views

Microfiltration for saturated solutions of highly hygroscopic compounds?

Is it possible to pass saturated solutions of compounds with very high solubility through filters with small pores (e.g. passing a saturated aqueous ZnCl2 solution at 90C through a 2mcm glassfiber ...
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1 vote
1 answer
58 views

Does adding NH3 to an HCl solution facilitate the dissolution of aluminum compounds?

If we compare the two solutions hereafter, which one would better leach/dissolve aluminum metal/compounds present at/near the inner surface of the glass: Solution A: $10\,\%\, \ce{HCl + H2O}$ Solution ...
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2 votes
0 answers
63 views

Appropriate ways to remove aluminum from the surface of glass?

I'm looking for a way to treat the surface of borosilicate glassware such that it won't contaminate solutions of puriss reagents in conditions that pure $\ce{SiO2}$ wouldn't, yet keep the bulk ...
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2 votes
1 answer
83 views

Trial by fire: Safely heating sand without it agglomerating?

Wikipidia quotes a melting point of 1713C for sand. I went on the beach to get some sand. I assume it's a mix of all kinds of stuff. The finality is to prepare a big pile of clean sand to use as ...
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1 vote
1 answer
26 views

How does functionalized activated charcoal work?

If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by exposing it to functionalizing compounds while heated to open up the ...
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2 votes
1 answer
168 views

Can I engrave borosilicate glassware without compromising its structural integrity?

Can I use a pen engraver (the kind that's like a tattoo gun with a diamond tip) to engrave my initials on labware without compromising it? I am in a lab space with a shared acid wash, and my glassware ...
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10 votes
3 answers
3k views

Is it better to use a smaller, more accurate measuring cylinder several times or a larger, less accurate one for the same volume?

I need to measure out 70 ml of liquid. I have a 10 ml measuring cylinder with a maximum uncertainty of 0.1 ml and a 100 ml measuring cylinder with a maximum uncertainty of 1 ml. I've calculated that ...
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7 votes
2 answers
4k views

How to identify a blow-out pipette?

Is my pipette a blow-out pipette? I suspect that it is a blow-out pipette, though the double lines aren't rings. My guess is it is a TC blow-out pipette. It's a big 50 mL pipette, longer than my arm. ...
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7 votes
1 answer
232 views

What is the purpose of this glassware?

I have seen these small test tube looking doohickeys being supplied from many chinese suppliers, but never with any description as to what they are for. They almost invariably have the description &...
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2 votes
0 answers
76 views

Does mercury react with polycarbonate?

Looking around at various material compatibility charts, they seem quite divided on the compatibility of metallic mercury and polycarbonate. Some sources (here, here, or here) indicate that ...
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0 votes
0 answers
225 views

What is the product of ammonia reacting with silicone?

I used a soft silicone hose to carry ammonia at ~70 °C. I was surprised to later find the hose had hardened. A quick materials compatibility search for silicone had given me a lot of info but an "...
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0 votes
0 answers
33 views

HDPE vs PP for storing pure aldehydes

I know both HDPE and PP have at least some degree of resistance to aldehydes, esters and aliphatic hydrocarbons. I am concerned however about minute contamination over time of pure samples and so I ...
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-1 votes
1 answer
44 views

Any plastic for long term storage of Puriss. Ethanol?

I'm being offered to share some puriss Ethanol. Can I store it long term in any plastic container without the slightest contamination/reaction from the plastic? I have HDPE, PET, but I could buy ...
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  • 889
4 votes
1 answer
616 views

Safest way to conduct a reaction with bromine under reflux conditions

I am conducting an electrophilic aromatic bromination reaction according to literature. The substrate and intended substitution pattern do not matter, but the reported procedure requires the dropwise ...
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0 votes
1 answer
55 views

Reduction by Activated Carbon

Does reduction by carbon itself occur when filtration is performed using activated carbon? Is it part of the central mechanisms involved in activated carbon filtration? One of the specificities of all ...
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1 vote
1 answer
51 views

Experience with PTFE tubing & glass connectors?

I'm wondering which PTFE tubing size to get to connect to normal 10mm OD glass connectors. For a silicon hose I would take an ID of 8-9mm as it is flexible but I think PTFE is quite rigid. Anyone has ...
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  • 889
1 vote
0 answers
108 views

What has happened with the pH-meter?

The glass sensor has became red inside like something melted. I stored it in a liquid with pH that mentioned in the manual. What is that and why could that happen, how often that happens with pH-...
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  • 305
9 votes
3 answers
1k views

Sintered vs perforated plate Büchner funnels

I just bought a sintered-glass style Büchner funnel for some vacuum filtration tasks. There's two issues I'm having with it: Filter material, especially activated charcoal, ends up stuck in the glass ...
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  • 1,092
1 vote
1 answer
605 views

when using glass to glass stoppers, is it best to have them dry or use lubricant?

I have some glass flasks that have glass stoppers. It’s basically the typical glass stopper with the frosted tip which fits into a glass opening. Basically think of a typical glass volumetric flask. i ...
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0 votes
0 answers
27 views

Affordable, non-contaminating flexible tubing for common acids

Which tubing material is affordable, flexible, widely available, and suited for transporting very pure acids ("puriss." products) in their most concentrated form without contaminating them? ...
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7 votes
1 answer
305 views

What kind of filter can remove zeolite dust from ethanol?

I only really have high school level knowledge of chemistry, and also I don't really own any lab equipment. I'm using 3A zeolite molecular sieves to dry ethanol (and sometimes isopropanol) and they ...
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  • 1,092
1 vote
0 answers
43 views

Is the width of a Soxhlet Condenser Inherent to its Function?

Soxhlet extractors are often coupled to a specifically designed condenser with a very large lower joint. Is this inherent to it's function as a condenser in the apparatus or only because the Soxhlet ...
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  • 889
0 votes
2 answers
75 views

Confused Reading of Pressure on Vacuum Gauge [closed]

I have a gauge used to measure vacuum but I'm a bit confused as the measurements state "Hg" (I would have supposed inches of mercury except it goes to -30) and "Bar" going to minus ...
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  • 889
0 votes
1 answer
344 views

What the difference in data if calibrate pH-meter with 2 and 3 solutions? [closed]

pH-meter (12 bucks one) can be calibrated with 2 different solutions (let's say 4.0 and 6.86), but as an option 3 can be used (4.0, 6.86 and 9.18). If I use 2 instead of 3, what error I'm going to get....
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1 vote
0 answers
59 views

Which Additives May be Present in Cellulose Filter Paper? [closed]

I'm wondering what, other than cellulose, might be contained in filter paper (the kind routinely used in Buchner filters / normal funnels). A search here on Chemistry Stackexchange shows that at least ...
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0 votes
0 answers
36 views

Compact way to regulate 3000psi (200bar) down to 30psi (2bar)?

This was originally posted on the Lego page, and closed because it's not actually about Lego itself. I thought I'd give them a chance first, in case someone had done this already and had some ...
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0 votes
0 answers
197 views

Looking for advice regarding a larger scale soxhlet extraction

I have successfully completed a few soxhlet extractions at a much smaller scale using a soxhlet extractor with ~200ml capacity. With that, I was able to extract from ~100g of pre-powdered, sonicated ...
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0 votes
1 answer
322 views

can i use an isobutane stove (like jetboil) or butane blowtorch with borosilicate glass?

I don't have a bunsen burner, but have a camping stove (similar to https://www.amazon.com/Stansport-183-B-Isobutane-Backpack-Stove/dp/B004EPWM5S) and a blow torch. I'd like to do some distillation ...
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-4 votes
2 answers
71 views

cheap anti-fog agent!

What are some safe and widely available alternatives to specifically formulated anti-fog sprays/treatments? Specifically for use on glasses, goggles, and face shields.
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0 votes
1 answer
52 views

Can a spectrometer be used to figure out spice ratios in a sauce?

There is a really good sauce that a local restaurant makes. I have had trouble recreating it, but have gotten somewhat close. I had the following idea: I could take an "image" of the sauce's color ...
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1 vote
0 answers
44 views

Mercury bulb on spirit thermometer?

I recently broke a Quickfit distillation thermometer and the bulb had liquid metal in it. I assumed it's mercury and acted accordingly. However, the column looks like spirit filled (blue liquid). Has ...
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  • 1,001
1 vote
0 answers
37 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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  • 11
-1 votes
1 answer
98 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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10 votes
1 answer
3k 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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2 votes
4 answers
145 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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0 votes
0 answers
53 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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1 vote
0 answers
53 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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