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
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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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
57 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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38 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
136 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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1answer
44 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
204 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
79 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
110 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
147 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
84 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
14 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 ...
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1answer
56 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
44 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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120 views

How to remove MEHQ from Methacrylic acid monomer without reduced pressure distillation?

I am aware that the standard way to remove MEHQ from Methacrylic Acid is to perform reduced pressure distillation. The papers I see suggest using ~ 10 Torr pressure to perform distillation. Sandler's ...
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1answer
91 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
34 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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42 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
17 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
65 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). ...
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1answer
132 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
70 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
39 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 ...
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1answer
1k 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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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 ...
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2answers
181 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
53 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
78 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
464 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 ...
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0answers
44 views

Why the etching profile of HF and HCl on titanium surface is different? [closed]

Why the profile of etched titanium with HF-HNO3 looks like a hill, while the profile of etched titanium with HCl is U-shaped? Can you please put your source if you know it? Thank you Note: the ...
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1answer
39 views

Which chemicals can counter the corrosion of tamperproof hardware encryption chips?

I'm moving from software implementations to hardware. I need to reverse engineer silicon chips, though the tech that I want to study may have a corrosive chemicals that's supposed to destroy the chip ...
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0answers
41 views

How to predict and measure excess values of reactivity ratios for copolymerization with three monomers?

I ask this question because I haven't found interesting literature on the subject and I would like to know if my way to think is good or pure bullshit. Also the question is quite long because I have ...
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1answer
766 views

What happens to the methanol formed by the hydrolysis of methyl 2-hydroxybenzoate (oil of wintergreen) when synthesising salicylic acid?

Here are the reaction equations for reference (you may recognise this as a preliminary step for the synthesis of aspirin). Steps for synthesis of salicylic acid: 1) methyl 2-hydroxybenzoate + sodium ...
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1answer
89 views

How can we measure the rate of reaction of EDTA chelation with zinc carbonate?

I am performing an experiment in order to find the activation energy of EDTA chelation. Consequently, I need to measure the rate of reaction of the process. I am high school student, and so I do not ...
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0answers
554 views

How are bond lengths measured experimentally?

How is the bond length between any two atoms in a compound measured? For example, in the case of graphite, the bond between its two layers is 340 pm. This number must have been measured, so what are ...
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1answer
225 views

Mathematical explanation of blank titration in Mohr method for argentometry

In my book it is written that in order to minimize systematic error in Mohr method for argentometry it is a common procedure to conduct a blank titration with $ \mathrm{Ag^+} $ against a $\mathrm{CrO_{...
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2answers
416 views

What happens to iron electrodes (attached to a battery) in copper(II) sulphate solution?

After a few hours, the following observations were made: The solution turns green. My guess: $\ce{FeSO4}$ is formed. There are reddish-brown and black powder deposits on both the electrodes. The ...
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1answer
135 views

Why does the rate equation between hydrogen peroxide and iodide ions not follow the stoichiometry of the rate-determining step?

The ionic equation of the reaction between hydrogen peroxide and iodide ions can be written as $\ce{H2O2 +2I- + 2H+ -> 2H2O +I2}$ which is the rate-determining step as well. From what I have ...
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3answers
333 views

How to determine if an unknown is potassium chloride or potassium bromate?

In class, we were given unknown substances. I've narrowed the possible substances down to either potassium chloride or potassium bromate. We were given several acids, indicators, and other chemicals (...
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3answers
184 views

Penny turns green with vinegar

What is the chemical explanation for pennies in vinegar turning green? What is the explanation at a macroscopic and atom-molecular level? The procedure is: Fold a paper towel so that it fits inside ...
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1answer
57 views

Units for density in nanorod image

I am counting the number of nanorods contained in a sample (see picture below). The length scale is 1 µm. What units does the density have? Is it µm-2?
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1answer
168 views

Last step of nicotine extraction using DCM

After using hydro-distillation method with distilled water and NaOH, separating the extract with dichloromethane, distillate it at 40 °C/104 °F, I'm left with some yellow pale oil. I'm just wondering ...
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0answers
201 views

What effect does an increase in concentration of copper sulphate solution have on the rate at which copper is deposited at the cathode?

I have been studying electrolysis in school and was wondering whether a higher amount of copper sulfate solution would produce a greater mass of copper in an electrolytic cell with two copper ...
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1answer
28 views

Find volume of sample such that it contains 100ng of DNA

Im struggling with the maths of concentrationsand volumes and things..Ill give the question, then my thoughts on it: A DNA trimer strand, ab, has moleuclar weight of $9309ng/\mu mol$. I#m designing a ...
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1answer
30 views

Activation energy of reactions

When a reaction occurs where does the energy to cross the activation energy comes from?My book states that it might look like there is violation of conservation of energy but the physics of small ...
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0answers
59 views

Formulation of a suspension of Magnesium Hydroxide

For a school project of mine, I have to formulate a suspension of Magnesium Hydroxide which contains at least 50% of solid matter. This suspension is prepared from Magnesium Oxide 98% with a ...
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1answer
113 views

what would happen if someone smell just a little chloroform? [closed]

I'm new in labratoary and a few days ago I smelled chloroform just for a second, out of curiosity. The next day I became very sick with symptoms like nausea, vomiting, fatigue and pain in my muscles. ...
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1answer
41 views

Turning Soda Glass into Lead Glass and Fused Silica [closed]

What would be the method of turning Soda Lime Glass into: A. Lead Glass B. Fused Silica Soda Lime Glass is $\ce{SiO2}$ ~70%. Lead Glass is $\ce{SiO2}$ ~ 62.9%. Fused Silica is $\ce{SiO2}$ ~ ...
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0answers
158 views

Determining the chemical formula of a polyiodide Salt

I've got a compound with formula $\ce{N(CH3)4.I(I2)_x}$. By mass I've got $\pu{0.138 g}$ of $\ce{I2}$ present out of $\pu{0.189 g}$ of polyiodide added. How do I find $x$? This is the exact part of ...