For questions relating to the theory, design or performance of chemical experiments, including theoretical structures, expected products, thermal calculations, and empirical analysis.
1
vote
1answer
37 views
Easy to do experiments that clearly show outstanding properties of graphene
By chance we received for free some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires at our University. I would like to prepare some very easy to do experiments for the ...
0
votes
1answer
31 views
Effect of substituting oxygen with sulfur in durg molecules
What sort of changes in the properties of organic or drug molecule can be anticipated if you substitute some or all of the oxygen atoms with sulphur atoms, and vice versa.
My interest in this ...
0
votes
1answer
52 views
What is the titre of a sodium hydroxide-sulfuric acid titration experiment?
So I did for my AS Level exam today a titration experiment, seeing how much sulfuric acid of (I think) about $0.100 - 0.200 \text{ mol dm}^{-3}$, which went in the burette, is needed to react with ...
-1
votes
0answers
21 views
reaction diffusion chemical elements [closed]
I am want to make an experiment of reaction-diffusion but I cannot find enough references. If anyone knows anything except the computational part of the experiment please respond. I want to learn more ...
3
votes
2answers
140 views
Presumptive test for modafinil?
Given a sample that is probably modafinil plus common fillers, but could be fake, what reagent tests would best determine whether it contains modafinil? Assume a known-good sample for comparison.
...
1
vote
1answer
43 views
Hot and cold air interaction in a sealed environment
What would happen if air heated to 1200 degree's Fahrenheit in a sealed environment was injected with colder air?
No specific pressure defined yet just a general idea of potential interaction between ...
0
votes
0answers
46 views
Ammonium hydroxide will produce a reddish brown precipitate when added to a solution of? [closed]
Ammonium hydroxide will produce a reddish brown precipitate when added to
a solution of :
A CuSO4
B Zn(NO3)2
C FeSO4
D FeCl3
1
vote
1answer
79 views
What is the procedure of designing a salt bridge for a galvanic cell?
I'm doing an experiment where I'm measuring the effect of changing the $\ce{Cu^{2+}}$ ion concentration on the voltage in a copper-zinc galvanic cell.
I'll be doing at least five trials for each of ...
4
votes
1answer
72 views
Can you create a buffer with a strong acid?
So I was wading through several textbooks yesterday reviewing the concepts of buffers. I found them lot more challenging than I used to. One thing in particular disturbed me: The books and internet ...
3
votes
1answer
58 views
Ambiguity synthesis
A paper says the following,
Dichloroglyoxime was prepared by chlorination of glyoxime in 10 % HCl at 0 deg C and crystallized from toluene.
When they say "crystallized from toluene" do they ...
3
votes
0answers
72 views
Clathrate Compounds with Quinone
I prepared a compound "$\ce{SO2}$-Quinolclathrate" by dissolving hydroquinone and sodium sulfite with hydrochloric acid in warm water.
After this, I tested a little sample of the product on a flame ...
2
votes
1answer
31 views
How are crystals formed from a gas?
In crystallization, crystals are formed from liquids by cooling.
How can crystals be formed from a gas by cooling?
2
votes
1answer
58 views
What components of safety should be included in a chemistry laboratory experiment conclusion?
The focus of my question here is this: In a laboratory there is a Bunsen burner, a hot plate, hydrochloric acid, and concentrated ammonia. What would you mention about safety precautions?
As ...
2
votes
1answer
70 views
How to compute the residence time for given flow rate in standard cubic meters?
I'm given a flow rate of of a gas mixture of $3\ Nm^3/h$ in standard cubic meters through a cylinder of length $50\ cm$ and cross section $70\ cm^2$, can I compute how long a particle will stay inside ...
4
votes
4answers
2k views
How to convert Carbon dioxide into Carbon and Oxygen?
How can $\small\cf{CO2}$ be converted into Carbon and Oxygen?
$\cf{CO2 -> C + O2}$
Alternatively:
$\cf{CO2 + ? -> C + O2}$
I know that plants are able to do this. But I'm wondering if it can ...
3
votes
1answer
132 views
Test presence of oxygen > 1%
I want to qualitatively test for presence of oxygen within argon gas. I would like the test to be positive if approx 1% or more is oxygen, but definitely negative if less than 0.1%. Anywhere between ...
3
votes
1answer
56 views
How do you determine the amount of acrylamide in foods such as baked fries?
There are many food studies which determine the concentration of a substance in a food item.
For example, this study determines the concentration of acrylamide in solid foods like fries.
By what ...
2
votes
0answers
48 views
How does a BET device function?
This is the theory behind BET. The theory is comprehensible
My question is more geared towards what is physically and chemically happening within a BET device to get a reading? How does a BET ...
6
votes
1answer
115 views
How to translate the mobile phase from thin layer chromatography to column?
I recently was told that once you find a good solvent mixture for separation on thin layer chromatography (TLC), you should only use 10% of the more polar solvent (for silica) when you run your ...
4
votes
3answers
131 views
MacGyvering a sealed tube
Is it possible (advisable?) to make a sealed tube by melting and twisting the end of a borosilicate test tube? One issue that I can think of is that the pressure might be too high if I then proceed to ...
5
votes
1answer
62 views
Detecting ethylene byproduct
I'm running a reaction that has ethylene gas as a byproduct. I have observed gas evolution as my reaction proceeded and I have other ways of verifying identify of the main product, but I thought it ...
10
votes
1answer
946 views
Choosing the right condenser
What are the advantages and disadvantages of the various types of condensers commonly found in the laboratory? Obviously more intricate pieces of glassware are more costly but assuming they are all ...
5
votes
1answer
182 views
What is the behavior of a Zwitterion during ion exchange chromatography?
We're interested in purifying a protein that has an azide moiety using ion exchange chromatography. Due to its unique structure, the moiety is a Zwitterion with a novel chemical behavior. My question ...
6
votes
1answer
651 views
What do the different grades of chemicals mean?
When purchasing chemicals from Sigma, Fisher, or wherever, there are often -grade's attached to their description like reagent-grade, technical-grade, analytical-grade, or more niche-sounding ...
5
votes
3answers
182 views
13C NMR spectrum only showing solvent
This is my first time taking a 13c NMR spectrum and while I'm aware the signal to noise ratio is much lower compared to 1H NMR, I didn't realize it was quite this bad. I took a spectrum and I only see ...
5
votes
1answer
224 views
What's the difference between precipitate and turbidity?
In many tests for various radicals, a "<color> precipitate" or "<color> turbidity" is mentioned. For example, lead ...
4
votes
2answers
966 views
Why are strong acids and bases not suitable as primary standards?
This is one of the questions with which I have puzzled over, and can arrive at no definite conclusion. Why are strong acids or bases, such as $\ce{H2SO4}$,$\ce{ HNO3}$, $\ce{HCl}$, and $\ce{NaOH}$ not ...
3
votes
2answers
536 views
Gas chromatography/mass spectrometry: Can I use peak ratios and molecular mass to derive quantity?
Can derive the quantity of a substance from a GC/MS report if I know:
the ratio to another substance in the data,
the quantity of that second substance, and
the molecular mass of both substances.
...
