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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26 views

Burnt/Oxidized Aluminium going invisible [closed]

I burnt an aluminium foil till I don't know if it's oxidized(AlO, Aluminium Oxide) or carbon molecules are formed on the surface, then submerged underwater then it turns invisible(the black(oxidized?) ...
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1answer
24 views

How to turn nickel into nickel 3 hydroxide

I have a sheet of pure nickel. Is is possible to turn the surface into nickel III hydroxide and How would I do it. Thank you.
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20 views

Chemistry of Paint [closed]

In a chemistry high school lab, what are the steps taken to produce paint using solvents and fillers? What materials and solutions would be needed to produce paint.
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1answer
120 views

How to make this citric acid substance I made not sticky?

So I made this solid material by boiling citric acid crystals and water then letting that cool to harden. It hardened into this solid that is really easy to mold and is transparent but it has this ...
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30 views

Why does a mentos make soda explode? [duplicate]

So if you put a mint mentos in a cup of soda it will explode everywhere. The mint in the mentos makes the soda have a chemical reaction which will then make the soda explode right? Well what would ...
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0answers
11 views

Why does changing the salt of the salt bridge (group 1 chlorine salts) effect the voltage produced in a galvanic cell?

My experiments results showed that the voltage decreases down Group 1 chlorine salts in the salt bridge. All other variables were kept constant. Zinc and Copper rods were used. Concentrations of the ...
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0answers
32 views

Suggestions for chemistry experiments to do regarding toxic gasses

I'm doing a final project on mustard gas, and need an experiment to conduct. I'm obviously not allowed to make or work with mustard gas, but what else can I do? Any other gas experiments that would be ...
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1answer
54 views

Solvent for reaction mixture

I'm looking for some suitable solvent for ether cleavage of Guaiacol (o-Methoxyphenol) using aluminium triiodide ($\ce{AlI3}$) with $\ce{DMSO}$. The original paper calls for using hot acetonitrile as ...
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1answer
30 views

electrochemistry experiment

something strange. i made an electrochemistry experiment in which i have measured the potential of cell: Ag, AgCl | (1M)KCl ║ [Fe(CN)6] 3-, [Fe(CN)6] 4- | Pt with different concentrations of Fe+2/Fe+...
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2answers
67 views

Is aluminium foil pure aluminium? [closed]

Is aluminium foil pure aluminium? Or does it have other elements in the e.g: tin (Sn) or lead (Pb)? Because when I try to oxidize it through the process of submerging it in water, it doesn't look like ...
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0answers
33 views

Explanation for differences between lattice enthalpy for MgF2 calculated theoretically and experimentally [closed]

Theoretically higher energy is released (−2915 kJ/mol) while experimentally less energy is released (−2908 kJ/mol). What is the explanation for it?
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2answers
3k views

Role of methanol in NaBH4 reduction

In reduction of carbonyls (aldehyde and ketones) to alcohols using NaBH4/Methanol, alkoxides are formed with the Boron which usually gets protonated on addition of water/acid. My question is what is ...
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28 views

How can a DPPH assay to measure antioxidant activity of beta carotene be conducted?

I am currently doing some research regarding beta-carotene. With reference to other sources and their methodoloy for DPPH assay, I conducted my experiment but failed to find any significant peak in ...
10
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1answer
2k views

Calculation of Atomic weight percentage in AAS

I am currently doing doping studies in a system similar to this ($\ce{A_{x}B_{1-x}}$) and I have to find atomic weight percentage of $\ce{B}$ element using atomic absorption spectroscopy(AAS). I have ...
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0answers
9 views

the reacrtivity series and displacement [closed]

when a shiny grey zinc granule is added to a blue solution of copper sulfate you will observe the following changes: -the zinc gradually disappears -the blue colour gradually fades -the mixture gets ...
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0answers
20 views

Can Methylene Blue Detect Spoilage in Food?

Initially, there is already a product which is a sensor based on Methylene Blue, which can detect changes in oxygen levels in a packaging. However, as our thesis project, we decided to take on this ...
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0answers
7 views

How should this DPPH assay be carried out? [duplicate]

I am currently doing some research regarding beta-carotene. With reference to other sources and their methodoloy for DPPH assay, I conducted my experiment but failed to find any significant peak in ...
-2
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0answers
25 views

How do I find % Sodium Hydrogen Carbonate and % Sodium Chloride in an unknown mixture using gravimetric analysis? [closed]

I was given this equation: 2 NaHCO3(s) + heat → CO2(g) + H2O(g) +Na2CO3(g). This was my data: Mass of Crucible:12.08 g Mass of Crucible Cover:12.42 g SODIUM HYDROGEN CARBONATE - TRIAL 1 ...
9
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1answer
2k views

Neutralizing a sulfuric acid spill

From my AP Chem Prep Book: What should you do if you spill sulfuric acid on the countertop? A) Neutralize the acid with vinegar. B) Sprinkle solid NaOH on the spill. C) Neutralize the acid ...
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2answers
59 views

Unusual Result in Kinetics Lab

The question: In the lab described below, why did the decolorization reaction described, which should be first order in each of the two reactants, go most slowly when the reactants were most ...
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0answers
23 views

Second order nucleophilic substitution (SN2)

How much time does the $\mathrm{S_N2}$ reaction of ethyl bromide (1-bromoethane) with 2 ml of 15% sodium iodide in acetone take? I did several experiments and using a hot water bath, it took around 17 ...
3
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1answer
86 views

Experimental measurment of thiosulphuric acid decomposition kinetics

Problem I am trying to do a kinetics analysis on the following reaction: $$\ce{Na2S2O3 {(aq)} + 2 HCl {(aq)} -> S {(s)} + 2 NaCl {(aq)} + SO2 {(g)} + H2O {(l)}}$$ Suggested Method However, most ...
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0answers
18 views

Extraction Techniques for Organic Compounds from Aqueous Media

I am looking to attempt an extraction of an organic compound that had just been prepared using a Friedel-Crafts acylation. The compound was prepared in MDC (~20 mL in total). After the reaction, the ...
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0answers
13 views

measuring the pKa of acetic acid in mixtures of water and methanol(changing percentage)

My goal is to measure the pKa of acetic acid in different mixtures of water and methanol, in which the proportion by weight of methanol will be changed. How can I measure the pH of this solution? Is ...
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1answer
40 views

Is there any aqueous solution (or simple method) to remove trace level of sulfur dioxide/nitrogen monoxide and nitrogen dioxide in a gas stream?

I need to generate pure gas from a gas stream which is free of $\ce{SO2}$/$\ce{NO}$/$\ce{NO2}.$ The air is already pretreated by activated carbon and purafil. However, I can't find any solution for ...
6
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1answer
373 views

How would you measure the rate of this SN1 reaction?

I am performing the following $\mathrm{S_N1}$ reaction: $$\ce{t-BuOH + HCl -> t-BuCl + H2O}$$ I would also like to measure the rate of this reaction, but I cannot seem to find a way. I initially ...
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1answer
21 views

How to increase volatility? [closed]

Is it possible to put a substance with low volatility into a highly volatile solvent, thus make the original substance also vaporize quickly? If not, are there anyway to increase it's volatility?
5
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1answer
519 views

The use of ice water in an experiment

An experiment from Vogel that I want to conduct requires "a mixture of ice and salt of about -10 °C". Reading trough the text it appears that I need at least 1-2 liters of this. Obviously the salt is ...
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1answer
346 views

Hydroxyl group to free amine in polyethylene glycol using CDI?

For converting $\ce{OH}$ of methylated polyethylene glycol. The first step is converting hydroxyl group to imidazole carbamate as an active intermediate. But what about the next step? If I will add ...
1
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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 ...
5
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1answer
69 views

How to recover C18 column after prolonged exposure to phosphate buffer?

A colleague of mine who occasionally does HPLC in a biochemistry lab discovered that a C18 column was not properly flushed after the previous experiment. It appears that the column was stored for ...
7
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4answers
14k views

How do I control the negative temperature in an experiment?

If one were to adjust the positive temperature in an experiment, they would use a heating plate, or a stovetop. How would one adjust negative temperatures in an experiment? (Not keeping the ...
21
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5answers
4k views

How would I measure the Carbon Dioxide content in Coca Cola over a period of time?

I'm sorry if this is a broad question, but I am trying to plan a simple experiment. I am wondering is there a somewhat simple way of continuously measuring $\ce{CO2}$. I already know the initial ...
1
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1answer
29 views

Role of phosphoric acid in redox titrations

For redox titrations of $\ce{Fe^2+}$ versus $\ce{KMnO_4}$ or versus $\ce{K_2Cr_2O_7}$ , role of phosphoric acid is quite unclear to me. In dichromometric titration, $\ce{H_3PO_4}$ complexes $\ce{Fe^3+...
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2answers
695 views

Removing aluminum oxide from impure silica

We have an assay for a mine. Our goal is to have only silica. Is there a cost effective way to extract the contaminants? The product is a fine powder called diatomaceous earth, or fossil shell flour. ...
3
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1answer
70 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 ...
5
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3answers
443 views

Zero filling leading to increases in resolution (NMR)

Zero-filling involves adding data points with zero intensity to the end of an FID. According to this website https://www2.chemistry.msu.edu/facilities/nmr/handouts/DH%20NMR%20Basics.pdf zero filling ...
2
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1answer
76 views

What reaction could rubidium undergo in a vacuumed chamber with Macor ceramic and glass?

In the center of the chamber on the photo below you can see the hexagonally-shaped Macor glass-ceramic consisting of Silicon dioxide $\ce{SiO2}~46\%$ Magnesium dioxide $\ce{MgO}~17\%$ Aluminum ...
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1answer
48 views

Is the rate of electrolysis the same throughout as long as voltage is same

In an electrolytic cell, where the electrolysis of dilute sulfuric acid is taking place, would the rate of electrolysis be constant always, even at the beginning? By rate of electrolysis, I mean the ...
3
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1answer
39 views

Calculating the total uncertainty of the final product

I have performed a large number of calculations in order to determine the ethanol content of wine. These included titrations using burettes, mass measurements using analytical balances, and others. I ...
10
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1answer
35k views

How do I calculate the concentration of sulphuric acid by a titration experiment with sodium hydroxide?

In my latest chem lab the objective was to create a primary standard of $\ce{NaOH}$ and use it to determine the concentration of sulfuric acid. The first part of the lab was determine the molarity of ...
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2answers
6k views

Titration of H2SO4 w NaOH: Solving for the molarity of H2SO4?

I am given $\ce{H2SO4}$ in a reaction vessel of about $50~\mathrm{mL}$. I need to solve for the molarity of $\ce{H2SO4}$. A $10~\mathrm{mL}$ sample of $\ce{H2SO4}$ is removed and then titrated with $...
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0answers
645 views

solubility trends of alkaline earth metals

Why is the solubility trend of group 2 oxalate compounds inconsistent with the actual order in the periodic table?
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0answers
11 views

Best desiccant for preserving large quantities of cotton

Without proper warehouse, freshly gathered cotton is piled in open air area spreading miles each way. It is covered by tarp during the rainy weather. What is a cheap/feasible method to keep it dry so ...
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1answer
32 views

Copper wire smoking underwater [closed]

I am doing an electrolysis experiment with two copper wires inside of test tubes that are both submerged underwater, with 20 V per wire. Test tube A is creating oxygen gas at a high rate, but test ...
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0answers
13 views

Starch Amylase Experiment using Iodine

The starch and iodide test is to detect amylose, a polysaccharide. We add an iodide solution to a sample and observe a color change with the starch; it turns dark blue. I am doing a bio/chem ...
0
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2answers
374 views

How to make copper salicylate with electrolysis?

I am trying the following and it looks like it may be working, but I am not certain what the end product would be. Basic electrolysis setup: two cups distilled water, with 3 g of copper wire on anode,...
0
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1answer
37 views

what wavelength should I use to measure the transmittance of iodine colouring? [closed]

I am doing an experiment on how pH buffers may affect amylase's break down of starch into glucose in a starch solution. I am using iodine reagent to identify how much starch is left after amylase is ...
1
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2answers
3k views

How to obtain calcium carbonate?

I read calcium carbonate is the main component of seashells and other animals' shells (such as snails), and also limestone. How can I prepare pure $\ce{CaCO_3}$? Could someone describe the process ...
1
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0answers
31 views

How to clean pocket pH meter before storage?

Hello. I read about different methods how to clean this specific(attached photo)pocket pH meter before storage and i can't figure out what is the right way. One method says to stir the pH meter(...