Questions tagged [experimental-chemistry]

This tag should be applied to questions relating to the theory, design, techniques or performance of chemical experiments. This includes but is not limited to theoretical structures, expected products, thermal calculations, and empirical analysis. Additional tags should be applied to narrow down the field of research.

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1answer
38 views

How to measure UV index? [closed]

I am a high school student so please apologise if I say something very dumb or irrelevant. I am conducting an experiment in which I want to find UV index at different points. Such as under shade, ...
2
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1answer
127 views

Is it considered safe to sonicate with flammable solvents?

I use a sonicator at work in a cleaning process. It involves sonicating acetone, NMP, and IPA. We would like to move forward with other flammables as well. We currently do the work in a hood, but no ...
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1answer
80 views

Is it possible to make polyethylene in a high school laboratory?

We learned how to make small amounts of ethene from ethanol using sulfuric acid. Is there a way to make a visible amount of polyethylene from that using materials I could get for a school lab? We can'...
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1answer
28 views

How much drinking water can I get back [closed]

If I was to boil a gallon of sea water and collect the condensation, how much drinking water would I get back?
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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
252 views

How can I use a solvent gradient in column chromatography? [closed]

I am working to use the column, there are a lot of videos which explain it, but I don't understand this statement in the procedure. The residue was finally purified by column chromatography using ...
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2answers
1k views

What is the real pKa of water?

What is the $\text{p}K_\text{a}$ of water? A simple google search yields the value $15.74$, but this site and this paper say it's $14.0$. According to my understanding, the correct answer should be $...
2
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1answer
193 views

Regarding Analysis for CO2 Absorption in NaOH

Background Lab experiment, packed glass column (random packing of metal/ceramic material), countercurrent gas absorption, flowrates measured using rotameters, $rt \approx 27^\circ C$. 2 N NaOH flows ...
11
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1answer
3k views

What is the role of ammonium chloride in the workup of a Grignard reaction?

In the following Grignard reaction, why is aqueous ammonium chloride used to get to the products? I don't see how it participated in or modified the reaction from what is normally expected.
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3answers
101 views

How Can I Induce Corrosion Electrochemically?

I'm very interested in measuring corrosion in metal alloys, particularly in salt solutions. I understand metals corrode over time, however, I was wondering if it's possible to electrochemically "speed ...
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1answer
410 views

How do I make a 0.5 M citrate buffer at pH 4.5?

I need to make a citrate-sodium citrate buffer at 0.5 M concentration and pH 4.5. I calculated the molarities of the citrate and disodium citrate based on the Henderson Hasselbalch equation, using a p�...
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1answer
530 views

Can an iodine clock reaction work without using a strong acid?

I'm going to do an iodine clock reaction for a project and we had to submit the materials and safety sheets for the experiment a while ago. I thought I could do one by using hydrogen peroxide, sodium ...
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1answer
628 views

How to effectively wash the precipitate or crystals on the filter and why?

My lab manual says that the precipitation on filter should be washed with a few small portions of the washing liquid. Why can't I just completely fill the filter funnel with the solvent instead of ...
2
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1answer
50 views

vapor pressure of one part of binary compound

Let's say we have a binary compound AB in an enclosed container, and let's say there's a tendency to form B-vacancies so that B atoms/molecules escape and form a vapor. Let's assume there's enough of ...
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1answer
165 views

Hydrogenation of 1-hexene with Raney nickel

For my high school senior chemistry project, I need to create and perform a lab. I've chosen to do the hydrogenation of 1-hexene with the catalyst of Raney nickel. I'm struggling because I'm not ...
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3answers
139 views

Changes in pH when adding substances other than acids or bases

If I start out with 100 mM acetic acid, what substance (to a final concentration of 1 M) could I add to change the pH considerably? I was thinking of NaCl or ethanol or acetone. Substances added ...
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1answer
33 views

Suitable safe cleaning solution for aliphatic urethane

I am looking for a suitable cleaning solution for a sprayed on coating that is an acrylic aliphatic urethane. My end goal would ideally be something that can neutralize rust, whiten and brighten the ...
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1answer
23 views

Taking a procedure for ICP and adapting it to use with AAS

I was reading a paper regarding metal detection and they gave their procedure for an acid digest of a soil sample which was then analysed by ICP-OES. They used nitric acid, hydrogen peroxide and ...
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0answers
291 views

Preparation of Saturated Salt Solutions - W/O Being Wasteful

Question What is the most cost effective way to prepare saturated solutions of each of these compounds? LiCl, K2CO3, and NaCl. Background I am trying to create a rudimentary controlled humidity ...
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0answers
35 views

XRD-Amorphous materials

I am interested in sealing some air-sensitive samples inside of xrd-amorphous material to allow for XRD and hopefully XRD-texturing analysis. Of course, Kapton is the common material used for this ...
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2answers
38 views

What's the use of adding 73 mM H2O2 to a supertanant? [closed]

Enzyme assays Determination of catalase specific activity The CAT (EC 1.11.1.6) enzyme activity was measured according to Gallego et al.38 Plant samples were grinded in $\pu{0.1M}\ \ce{...
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1answer
24 views

Dilution of Concentrated TiCl4 using deionized water [closed]

How can we dilute conc TiCl4 (>99%) to 20 % w/w, using only DI water?
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0answers
31 views

How to Separate Copper Nanowires in an Alumina Membrane

So, in my Chemistry Lab we had an experiment to use Whatman alumina membranes and GaIn eutectic to create Nickel nanowires through electrodeposition. So essentially Nickel wire electrode and alumina ...
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1answer
79 views

I need some help on this Chemistry question can any one help please!! I need to find the cost of a single atom of aluminum [closed]

A 75 ft2 roll of aluminum foil costs $3.79. A 12"x12" pieces has a mass of 1.0 g. How much does a single atom of aluminum cost, in dollars? i need to show all my work i am so lost.
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1answer
46 views

Is it possible to displace cerium from cerium sulphate using aluminium to get pure cerium metal?

I'm unable to find cerium any reactivity series, hence the question..
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1answer
211 views

questions about the synthesis of iodobenzene from aniline

I am conducting an experiment about synthesis of iodobenzene from aniline, referring to this site(and various sites) (http://www.prepchem.com/synthesis-of-iodobenzene/). Below is my experimental ...
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2answers
89 views

Troubleshooting electrochemical batteries

For my science classes, I have built multiple types of electrochemical batteries utilizing oxidation-reduction reactions, and I have demonstrated that they each produce potential difference across the ...
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0answers
311 views

Confusions regarding porous pot experiment

So, I have studied about the porous pot experiment.Although I did understand the concepts of water level falling and rising due to difference in RMMs and thus difference in rate of diffusion, I ...
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1answer
122 views

How to distinguish between an insoluble ionic compound and an insoluble metallic compound? [closed]

Insoluble ionic compounds and insoluble metallic compounds could both have high melting points, insolubility, and no conductivity in water. Is there a way to distinguish between the two in a ...
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3answers
175 views

Is there a way to oxidize salicyl alcohol to salicylic acid without using chromium trioxide? [closed]

I'm doing a project for school and I need to convert salicyl alcohol to salicylic acid, but I'm not allowed to use $\ce{CrO3}$ because of its toxicity. I know it is also possible to oxidize a primary ...
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1answer
321 views

Diluting topical cream (10%)

I need to dilute a face cream with 10 % active ingredient to 2.5 % and 5 % but I am confused as to how. I looked into the $$c_1V_1=c_2V_2$$ and $$\text{concentration of a solution}=(\text{amount of ...
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1answer
127 views

Is the relative humidity of pure water vapour 100%?

If there is pure water vapour in the gas phase, can the partial pressure be taken to be equal to the vapour pressure of water at that particular temperature? edit: How is relative humidity calculated ...
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1answer
15 views

If copper becomes copper oxides because of oxygen in the air, is it a competing reaction? [closed]

If copper becomes copper oxides because of oxygen in the air, is it a competing reaction? My science class made pure copper with a simple displacement reaction. We let it set on the window to let it ...
2
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1answer
58 views

How could I produce/rig this flame-colour lottery?

Not sure if this is the wrong SE for this, happy to move it if not... In the Netflix TV series Sabrina, there is a scene where people take part in an appropriately-gothic-and-ominous lottery, which ...
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1answer
124 views

How to assess sunscreen effective via blueprinting?

How do I assess the effectiveness of sunscreen creams by using the blueprinting process? I know blueprinting is done when something is sensitive to light and this may cause reactions to produce a ...
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1answer
172 views

Extrapolating from a calorimetry lab to find a new delta T with different volumes and grams of substance

So, we just finished an AP chem lab where the question was basically: Given the results of the lab were that $\pu{5 grams}$ of $\ce{CaCl2}$ and $\pu{45ml}$ of water produced a $\pu{13.33 ^\circ C}$...
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1answer
16 views

How to measure and transfer suspensions?

I need to measure and transfer 10 ml of a fairly dilute suspension at a time to another container. But no matter how diligently I do it, sedimentation happens quickly after mixing and successive ...
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1answer
43 views

emulsion - why does it make a differnce if you have have more/less water/oil

So I have been wondering why you can see the following: Using 10 ml oil and 1 ml water with and emulgator leads to a way better emulsion than if you use 10 ml water with 1 ml oil (if you use the ...
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0answers
46 views

Acid-base extraction lab exercise

I have a solid mixture of trans-cinnamic acid and menthol. I’m new to this organic chemistry business and I don’t know if I can react the acid directly out of the solid mixture with a basic solution ...
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1answer
19 views

How to loosen up Tris HCl?

I have this bottle of Tris HCl that I need to use and apparently it's all hard. I don't have time to get a new bottle since this is needed for a lab for tomorrow and this is all I was given. Is there ...
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1answer
116 views

Protection of Alcohol

I carried out an experiment and it goes like this: 2-bromoethanol + dihydropyran (DHP) ---> 2-(2-bromoethoxy)oxane Acidic ion exchange resin was added alongside as a source of H+ ions (catalyst). ...
4
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1answer
147 views

Melting of ionic compound hydrates

My professor asked us the reason of the melting point of potash alum being so low, despite it being an ionic salt. He later went on to answer it by saying that melting point is a misnomer for the ...
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0answers
74 views

How to decide if a salt is soluble in water through mere pen and paper [closed]

In the laboratory we are given numerous salts for analysis for cation and anion. How can one decide which combination of cation and anion cannot form soluble salts in water so that after detecting an ...
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1answer
52 views

Can sucralose form a syrup?

(Almost) Everyone is familiar with making simple syrup from table sugar and water. I was wondering if pure sucralose is also capable of forming a syrup. I wanted to do an experiment myself, but to ...
5
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1answer
2k views

Reaction of chloroform, resorcinol and strong base

A common reaction used to identify resorcinol (benzene-1,3-diol) in the laboratory is to react it with chloroform in presence of 30% sodium hydroxide (NaOH). A red coloured solution (or precipitate) ...
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0answers
35 views

What does “off-hue” constitute in the context of analyzing a sample using the Pt-Co color scale?

ASTM D1209, the method describing how to perform the Pt-Co color scale test for a sample, recommends reporting material that can't be matched to a particular standard as "off-hue". For color based ...
2
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1answer
265 views

Can chiral atoms have same substituents but with different orientations?

So consider this molecule. We have to determine whether nitrogen atom is chiral or not. MY IDEAS: Now going by all I have read, for chiral atoms only criteria is substituents to be different. Here ...
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1answer
57 views

How can I prevent the effervescence of a solvent during evaporation? [closed]

How can I prevent the effervescence of a solvent like petroleum ether when I evaporate it on a water bath?
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2answers
90 views

How to evacuate a glass vessel containing powders?

I would like to evacuate a vessel (a glass round-bottomed flask) and which contains a few grams of platinum. However, I am worried about the platinum powder being sucked up by the vacuum. A few ...
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2answers
624 views

Obtaining calcium iodide from calcium and iodine

According to: https://www.webelements.com/calcium/chemistry.html Calcium reacts with iodine upon heating as follows: $\text{Ca}_{\,(s)} + \text{I}_{2\,(g)} \to \text{CaI}_{2\,(s)}$ I am ...