Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

1
vote
2answers
29 views

At what position in the distillation apparatus does the temperature match the boiling point of the distilled substance?

A student is separating $\ce{CHCl3}$ (bp = $\pu{61 ^{\circ}C}$) from $\ce{CHCl2CHCl2}$ (bp = $\pu{146 ^{\circ}C}$) by distillation. She has just begun to collect the first distillate in the receiving ...
1
vote
0answers
15 views

Is the iodide and persulfate reaction bimolecular?

Given the following reaction in an aqueous state: $$ \mathrm{2I^- + S_2O_8^{-2}\rightarrow I_2 + 2SO_4^{2-}}$$ Is it bimolecular o trimolecular? Because two molecules of iodide react with one ...
0
votes
0answers
14 views

Expanding upon an Experiment [on hold]

We've been tasked with a Depth Study for my Chemos class, and it has to do with indicators and the pH scale. So far, I've created an indicator using red cabbage and have applied it to different ...
0
votes
1answer
11 views

Calculating the Presence of Anthocyanin in a Solution

I've produced a red cabbage solution (boiling red cabbage in water basically), and would like to calculate the concentration of the red cabbage/anthocyanin in the solution. How is this accomplished? ...
1
vote
0answers
24 views

Pyrophoric nature of Raney Nickel

I am about to do a hydrogenation lab, and a, struggling with how to prepare my Raney Nickel so it does not spontaneously ignite during my lab. Most websites say to just submerge it in water– is this ...
-2
votes
1answer
44 views

Titration of 0.2 M KOH with 0.05 M HCl [closed]

I need to use the following example to calculate the acid base reaction for the titration of $\pu{0.2 M}\; \ce{KOH}$ 0.2 N with $\pu{0.05 M}\; \ce{HCl}$ 0.05 N of a sample that produces $\ce{CO2}$. ...
0
votes
1answer
43 views

how to calculate the initial concentration of NaOH in a mixture? [closed]

I have doubts about how to find the equation for the calculation of the initial concentration of $\ce{NaOH}$. I have the following information: in the kinetic study of a reaction, We measure $\ce{20....
-1
votes
0answers
28 views

How to Make Paraffin Cubes that are flammable? [closed]

I have paraffin wax, I need to make cubes like weber cubes if you search online, and can I lower the melting point of paraffin using any other substance?
0
votes
1answer
39 views

Why does the colour of gold sol change with particle size? [duplicate]

Regarding the colour of gold sol, my book says Finest gold sol is red in colour; as the size of particles increases, it appears purple, then blue and finally golden. This is the image I found on ...
3
votes
2answers
62 views

No current in homemade galvanic cell

I built a galvanic cell using 0.01 M solutions of copper sulfate and zinc sulfate. I used copper and zinc electrodes and immersed them into the proper solutions (copper into copper sulfate, zinc into ...
0
votes
0answers
21 views

How does hydrated salt lose water?

Hydrated salt—-> anhydrous salt How do I determine the temperature and time needed to turn all the water to steam?
4
votes
1answer
32 views

XAS spectroscopy - Differences in magnitude of 2p SOC and 3d SOC?

Within L-edge x-ray absorption spectroscopy, the spin-orbit coupling within the 2p shell results in the splitting of the L edge into L3 and L2 edges.As given in the following paper http://dx.doi.org/...
-1
votes
1answer
67 views

How to determine Acid-Base Indicator [closed]

How do we determine which is the best indicator to use when given the initial pH’s of both the acids and bases and the endpoint value of our base?
0
votes
0answers
35 views

Developing a lab to identify the concentration of casein in organic milk

I am currently attempting to create a feasible lab design that will enable me to identify the concentration of casein protein in organic milk without having to use spectroscopy. Thus far I have ...
0
votes
0answers
15 views

Why does alpha alumina have less surface area than gamma alumina?

Its been documented extensively that when gamma alumina (cubic) changes into alpha alumina (hexagonal) at temperatures around 1200 °C the specific surface area reduces considerably. What are exact ...
1
vote
2answers
36 views

Is there a replacement for glacial acetic acid in determining peroxide value

I am not allowed to use glacial acetic acid at my school, which all procedures online for finding the peroxide value of oils use through an iodometric titration. Is there a replacement?
1
vote
1answer
28 views

Is it more precise to measure a substance as a solid or as a liquid?

If I have a substance and want to obtain an exact quantity of it, is it better to measure it as a solid or as a liquid? In other words, if I have, for example, NaCl crystals I can weigh the crystals ...
3
votes
2answers
58 views

What does the reaction of hydrogen and iodine to hydrogen iodide look like?

The reaction, $\ce{H2 + I2 <=> HI}$ is often used as an example for equilibrium reactions. It is however a difficult reaction to show in a school laboratory: we are not equipped to work with ...
5
votes
2answers
71 views

Should the tip of the burette of an automatic titrator be immersed in the analyte?

In all the tutorials I found online, the tip of the burette (containing the titrant - NaOH) was immersed into the analyte solution. My question is: shouldn't the tip be out of the solution? Isn't ...
0
votes
1answer
34 views

How can I Identify Elements in Objects? [closed]

Since all objects on earth are composed of elements, how can I identify the fundamental make-up of objects such as trees, glass, bricks, wood, plastic, shoes, and other entitys?
3
votes
1answer
26 views

How can I prevent my spin-coated silica thin film from cracking when I heat it up?

I am spin-coating a porous silica solution on a glass microscope coverslip, and then heating the resulting thin film to $\pu{350 °C}$, in an attempt to create a thin film of porous silica sol gel. I ...
0
votes
1answer
38 views

Simple alternative to UNIFAC to prove that a mixture containing 1ml of x and 5 litres of propylene glycol is not flammable?

Section 2.6.1 of the REGULATION (EC) No 1272/2008 (CLP) defines a flammable liquid as: Flammable liquid means a liquid having a flash point of not more than $60 ^{\circ}$C. So data on flash ...
1
vote
2answers
50 views

Precipitation of AgCl from the tap water solution of the group 2 chloride

I had this question about an experiment where the group 2 chloride was dissolved in distilled water and excess $\ce{AgNO3}$ was added to the solution to form $\ce{AgCl}$ precipitate. One of the sub-...
1
vote
1answer
24 views

Which reactions occur during the oxidation and dissolution of bromide/bromine?

I'm trying to understand the fate of bromide anions during and after they undergo anodic oxidation. I have a solution of 94% DMF/6% water (by volume) with 0.1 M tetrabutylammonium bromide (TBAB) as ...
1
vote
1answer
67 views

Applications of magnesium sulfate monohydrate MgSO4 · H2O

How is magnesium sulfate monohydrate $\ce{MgSO4 * H2O}$ used for in chemistry and how does it work as a valuable laboratory drying agent? I could not find too much information in my book or the ...
0
votes
1answer
28 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
votes
1answer
29 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 ...
1
vote
1answer
45 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'...
-2
votes
1answer
24 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?
17
votes
1answer
2k views

What's this glassware?

Can anybody tell me what this glassware with a stem, bulb and long tube is?
-2
votes
1answer
25 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 ...
0
votes
2answers
97 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 $...
1
vote
1answer
49 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
votes
1answer
692 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.
0
votes
2answers
49 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 ...
0
votes
0answers
20 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 ...
1
vote
1answer
98 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 ...
1
vote
1answer
46 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 ...
1
vote
1answer
34 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 ...
0
votes
0answers
23 views

Metal colored flame and safety

For Chrismtas I was a given a wonderful gas lighter, that produced a pink flame by heating small metal pads (when the pads are cold, the flame is blue, once they are red hot, the flame is colored). ...
1
vote
1answer
82 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 ...
0
votes
1answer
19 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 ...
0
votes
1answer
14 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 ...
1
vote
0answers
47 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 ...
2
votes
0answers
25 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 ...
-3
votes
2answers
33 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{...
-1
votes
1answer
20 views

Dilution of Concentrated TiCl4 using deionized water [closed]

How can we dilute conc TiCl4 (>99%) to 20 % w/w, using only DI water?
2
votes
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 ...
-3
votes
1answer
41 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.
0
votes
1answer
34 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..