For questions relating to the theory, design or performance of chemical experiments, including theoretical structures, expected products, thermal calculations, and empirical analysis.

learn more… | top users | synonyms

1
vote
0answers
17 views

To model early fluid flow which types of pumps should be used?

I have I microchannel test rig , I want to push a 150-300 ml/hr from water in my test , I would like to know which pump type i can use ?
0
votes
1answer
41 views

Compare Catalysts in Calorimetry Reaction

I am writing a lab report and need some help understanding something. I have performed a calorimeter experiment and compared the different reactions that were taking place inside it with a ...
5
votes
1answer
48 views

Steam distillation- how it actually works?

To obtain phenylamine after it is formed from the reduction of nitrobenzene with tin, we carried out steam distillation. This is what I learned in class: "During the process,steam is injected ...
-1
votes
1answer
49 views

How alkanes can be prepared by aldehydes and ketones? [closed]

Preparation of alkanes by aldehydes and ketones, its chemical reaction and mechanism.
4
votes
2answers
76 views

Getting to use the lab!

Today I finally mustered the courage to go and talk to the director of the labs to politely ask him if I could use the labs out of class hours. Long story short, our lab sessions "are bad" because we ...
3
votes
3answers
53 views

How do I create a concentrated solution of singlet oxygen (in the dark)?

Without appealing to reactions that require photons / light, how do chemists achieve a very high concentration of continually produced, though quite short lived, singlet oxygen in aqueous solution ...
0
votes
2answers
64 views

What does “EM grade” mean

I'm looking at purchase orders and I see purchases for chemicals like the following. Glutaraldehyde, EM Grade, 25% What does the "EM Grade" mean in this text? It says that it's recommended for ...
0
votes
0answers
176 views

How to calculate lattice parameter only using planes and d spacing

I am trying to find lattice parameter of a hexagonal crystal, usually i uses cellcalc for calculating lattice parameter of a crystal struture. In that software it asks only two queries one is details ...
3
votes
0answers
14 views

How to get defect-energy level diagram from PL data

I am reading this article Phys. Chem. Chem. Phys. , 2011, 13, 14902-14905 and seen that the authors have drawn a image of defect level using PL data Can you explain me how this diagram can be drawn ...
6
votes
1answer
3k views

Chemistry behind Gale's Coffee Maker in Breaking Bad

Is there a scientific basis for the coffee making equipment which Gale describes in Breaking Bad? He talks about maintaining the right conditions for bringing out the coffee flavor without degrading ...
1
vote
1answer
45 views

Changes in defects in a material due to heat treatment

Currently i am doing some research on optical properties of a oxide material and for that purpose i have done some photoluminescence study on it. Because this is an ongoing research i cant divulge ...
1
vote
1answer
44 views

Why does MgCl2 lower the freezing temperature, and how does it do so?

I am working on a project in my chemistry class, and even though we've already finished the lab, I'm still confused as to why and how $\ce{MgCl2}$ melts ice/ lowers the freezing temperature of water. ...
3
votes
0answers
203 views

Calculation of Atomic weight percentage in AAS

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

A volumetric analysis experiment

I completed a titration experiment in a lab. The aim was to find the concentration of the titrant KMnO4 solution by titrating it with a sodium oxalate solution of a known concentration. I first made ...
0
votes
1answer
417 views

How is iron(III) chloride changed from solid to solution?

I'm conducting an experiment using iron(III) chloride in aqueous solution, but am also aware that it's usually a solid. How is iron(III) chloride experimentally converted to a solution? And can you ...
2
votes
1answer
281 views

How would one go about making a cheap freeze spray?

I'm interested in making a liquid freeze spray, for a fun science project. My only experience with this comes in spraying inverting canned air dusters, which spray a -60F mist/liquid (liquid if you ...
1
vote
1answer
57 views

preparation methods of nicotinoyl glycine

How can we prepare nicotinoyl glycine from nicotinic acid ?Is that possible by reaction between nicotinic acid and glycine?
1
vote
1answer
92 views

$\beta$-mercaptoethanol molarity

I'm writing up a practical and $\beta$-mercaptoethanol was used, with no concentration given. I've found I don't need the BME molarity since I'm giving percentage (v/v) concentration, however I'm ...
2
votes
1answer
81 views

Why is nicotinoyl chloride available as its hydrochloride salt? How can we separate them?

Nicotinoyl chloride is only available as its hydrochloride salt. Why can't nicotinoyl chloride be synthesized in free form? How can we seperate nicotinoyl chloride from its salt form? Can we try any ...
5
votes
2answers
115 views

Removing Ti from Ta Crucible

I'm trying to remove titanium filling from a tantalum crucible for a high-temperature effusion cell. I've managed to get a majority of the material out with tweezers, but some remains and is ...
2
votes
1answer
391 views

Effect of dillution on titration

When we are titrating acid/base using ph meter we add distilled water to immerse the ph electrode. Won't this affect the concentration of the acid/base: I mean isn't this dillution. Won't this ...
2
votes
1answer
449 views

Why is a theoretical titration curve higher than a practical one?

I'm currently in high school and I did two titrations. The first one is a titration of $10.0$mL $0.1$M $\ce{HCl}$ with $x$ mL $\ce{NaOH}$. I obtained the following titration curve: The blue curve ...
3
votes
1answer
159 views

Easy-to-do experiments that clearly show outstanding properties of graphene

By chance, we received some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires for free at our university. I would like to prepare some very-easy-to-do experiments for the ...
0
votes
1answer
111 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
334 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 ...
3
votes
3answers
508 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
119 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 ...
5
votes
2answers
475 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 ...
5
votes
2answers
178 views

Potential diffrence between two graphite strips in NaCl solution

I have two identical graphite strips of dimensions 3.5cm by 1cm. Both are 3/4 submerged in aqueous NaCl solution (0.34mol/dm3, 2%wt) with a distance of 7cm apart. I attached crocodile clips to each ...
4
votes
1answer
267 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
76 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 ...
4
votes
1answer
177 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 ...
1
vote
1answer
40 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
124 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 ...
3
votes
1answer
138 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 ...
6
votes
5answers
13k 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 ...
4
votes
1answer
249 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 ...
4
votes
1answer
62 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 ...
3
votes
1answer
90 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 ...
7
votes
1answer
172 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 ...
5
votes
3answers
172 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 ...
6
votes
1answer
113 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 ...
12
votes
1answer
5k 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 ...
6
votes
1answer
277 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
3k 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 ...
6
votes
3answers
289 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
391 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 ...
6
votes
2answers
3k 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 ...
5
votes
2answers
1k 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. ...