# All Questions

29,903 questions
6 views

### Atomic molecular theory [on hold]

Two pure gases of elemental composition X and Y are allowed to mix in a chamber. When combined, these two gases produce a liquid with the chemical formula XY2. Interestingly, the liquid product has ...
28 views

### Addition v/s elimination with double bond and OH together

If a compound has both an hydroxyl group and a double bond and we add $\ce{HBr}$ to it, (a) substitution reaction to the hydroxyl group can take place, or (b) an addition reaction of a ...
15 views

### Calcium chloride and calcium chloride dihydrate difference [on hold]

I need to prepare 0.2 M Calcium Chloride but I have Calcium Chloride Dihydrate instead. So how do I make the calculations in that case?
40 views

### Why are yields of some chemical reactions so dependent on the stoichiometry of the reagents? [on hold]

Back in chemistry class in high school I was working with a partner doing a chemical reaction. We measured the amounts of reagents well, but not perfect, and our yield suffered greatly. On the other ...
15 views

### What is the cause for the difference in pH between NaCl and Ringer Lactate

Reading this article, I came across a passage which got me to think of this question: "Normal saline contains approximately $\pu{154mM}$ of each $\ce{Na+}$ and $\ce{Cl-}$ with average pH of 5.0 and ...
26 views

### What value should I use for P in the ideal gas equation for an unknown molar quantity?

I did a chemistry lab, in which baking soda and vinegar were reacted in a ziplock bag, and I was to calculate the proper quantity of reactants to fill the bag with CO2. The molar quantity of gas was ...
44 views

### How does 1-bromo-2-fluorobenzene react with lithium amalgam? [on hold]

How does this organometallic reagent react with 1-bromo-2-fluorobenzene? Does it react like Grignard reagent? If the product of this reaction is then reacted with furan, what will be the final product?...
65 views

### Mechanism of DPD (N,N-diethyl-p-phenylenediamine) reaction with free chlorine

NOTE: As I've been finding new informations about the question, I've been editing the question to keep it up to date. If some comment doesn't make sense just check the Edit History. DPD (N,N-diethyl-...
20 views

### How do you remove lumps in reagents without contaminating them?

I think desiccating the powdered reagent would help remove lumps (at least in preventing lump neoformation) but would desiccation alone collapse all lumps in a powder (say KCl as it lumps easily), or ...
20 views

### NMR of trigonal bipyramidal molecules

I'm slightly confused about NMR. I seem to remember at school that if a molecule is symmetrical in $\ce{^1H}$ NMR, that only one peak would be shown e.g. propane's terminal $\ce{-CH3}$. Consider ...
105 views

### Why does ordinary water have a triple point?

Triple points and triple lines for pure substances and mixtures My understanding is that pure substances can have triple points. But mixtures of substances have triple lines, i.e. there isn't a ...
40 views

### what is mechanism for reaction phenol + dimethylsulphate -> anisole

Dimethyl sulphate breaks the oh bond and forms anisole. How does the reaction proceed?? is it oxygen lone pair attacks on sulphur which has partial positive charge?? the reaction takes place in ...
20 views

### NMR for an octahedral complexes sources of peaks

I wanted to ask a question about splitting pattern in NMR. I was given the following information to assign to a Compound C and justify why the splitting patterns are as given: I was confused about ...
21 views

### The number of maxima in 2s orbital are? [on hold]

What is the number of maxima in an 2s orbital? I have no idea what a maximum is here.
13 views

### Electroplating on Brass - Specifics [on hold]

I'm familiar with the basics of electroplating but not with the specifics; I want to do chrome plating on brass to give it a finish, I know that first there is an acid bath, then nickel plating, and ...
27 views

### Acid and base separation on an anion exchange column [on hold]

I'm new with this concept and so I would need some advice. I want to separate an acid and a base in a water solution. The acid has $\mathrm{p}K_\mathrm{a}(\ce{HA}) = 5$ and the corresponding acid of ...
22 views

### Is there a difference between nylon-6,6 and polyamide-6,6? [on hold]

Like the title says, is there a difference between nylon-6,6 and polyamide-6,6 or are those just synonyms?
21 views

### Synthases vs Lyases - nomenclature

Lyases are a class of enzymes that break down (lyase: ly- = lysis, -ase = enzyme) bonds like $\ce{C-C, C-S}$ and so on (except hydrolysis), and can eliminate molecules like $\ce{H2O}$ or $\ce{CO2}$. ...
23 views

### What kind of algorithm does computational software use to process molecular symmetry?

Background I'm forced into using GAMESS-UK for an older software package. Using a cs-symmetry molecule, I've noticed that GAMESS will reorient the molecule before running a standard SCF calculation. ...
19 views

### Formation of charge carriers in HFCs

In a conductivity cell with a dielectric HFC liquid e.g. R134a (i.e., 1,1,1,2-tetrafluoroethane) between two electrodes, when applying a high voltage, how does current flow across the electrodes? Does ...
41 views

### What is the line cutting benzene ring? [duplicate]

There is a line cutting benzene ring what is that called.
27 views

### How to reverse copper electroplating?

We did a lab where we built a simple electrolytic cell. In a beaker was a solution of $\ce{CuSO4}.$ A copper strip (anode) and a copper wire (cathode) was place in it. A wire connected the copper ...
967 views

What is "dot" sign in •NO? I know that it is radical nitric oxide, but I don't know if it is necessary to put the "dot". Is there any difference between •NO and NO?
115 views

### Why do solutions of electron in a box (and in a ring) predict coefficients for LCAO (linear combination of atomic orbitals) in 1D systems?

The solutions to the 1D particle in a box quantum mechanic system are standing waves (zero at both ends of the box) with 0,1,2... nodes for increasing energy (zero for the ground state). If I look ...
20 views

### Controlled chlorination of methyl group of toluene

I've seen a reaction in which tolune is converted to chloromethyl benzene and another to dichloromethyl benzene, both with the conditions Cl2, PCl5. If this is a radical mechanism, could you control ...
20 views

### How to find the compounds in a solution/material [on hold]

I am trying to find the components (Nitrates, Magnesium, Sulphur, Calcium, Iron, etc) in my organic manure. If I mix manure in distilled water how do I measure the presence of all the elements in the ...
17 views

### PAA co PMMA why metacrylic unit is needed?

There is a copolymer of polymethyl metacrylate and polyacrylic acid. What is the point in putting pmma units? What do they bring into polymer?
43 views

548 views

### Testing thermite for chemical properties

I'm writing a movie in which a bunch of military explosive ordnance experts destroy a turbine with thermite and the local fire chief has to work out whether it is plain $\ce{Fe2O3}$ and aluminium ...
230 views

### How are neutral amines effective bases in organic chemistry?

I have found it to be rather strange that neutral amines, such as triethylamine or DIPEA, find applications in organic chemistry in deprotonating alcohols or even α-carbonyl compounds. Amines are ...
33 views

### Band MO of Sodium Filling of electrons confusion

I wanted to ask a question about metallic bond - band electron theory. Consider the diagram of Sodium below: Circled are orbitals both containing $2$ electrons each which combine using LCAO to give ...
16 views

### How can you discover mass percentage from Molar mass? [closed]

A collegue told me that you could find out the mass percentage of the elements
21 views

### How many carbon atoms are there in a diamond (pure carbon) with a mass of 48 mg [closed]

I am stuck on this question for homework and not sure how to do it.
22 views

### heat of hydrogenation, putting the molecules into a right order [on hold]

could anyone help me with this question out?: I should put the molecules in a rising order in terms of the heat of hydrogenation. 1-Butene, (E)-2-Butene, 2-Methyle-2-Butene, 1,3 Butadiene,(Z)-2-...
43 views

### Applying vacuum at the end of a flash chromatography column

I know that flash chromatography uses a positive or pushing pressure to achieve the goal which is separation. Would the same goal be achieved if you had a vacuum on the other end instead of a ...
23 views

### Hydrolysis of an amidine derivative under acidic conditions

I know that an imine can undergo acid hydrolysis to yield a corresponding amide: https://chem.libretexts.org/@api/deki/files/13283/10.jpg?revision=1 But I am looking at a mechanism for acid ...
31 views

### Synthesis for turning synephrenine into N-methylphenethylamine

I am trying to devise a synthesis to change synephrine (4-[1-hydroxy-2-(methylamino)ethyl]phenol) into N-methylphenethylamine. I was figuring that I could remove the hydroxyl group attached to the ...
45 views

### Enol content tautomers

I have figured out that 4 one will have the highest enol content of all, and the 1 structure would come after 4 in enol content, i.e 4 > 1. Then I got confused between the 2nd and the 3rd structures. ...
15 views

### Cleaning copper electrical conductors [on hold]

I have some oxidization and scale build up on the water cooled copper electrical conductors. I woud like to use a viniger/salt solution to decsale and clean the inner bore of the copper electrical ...
41 views

### Why isn't aluminum ferromagnetic?

I know that the ferromagnetism of iron is because of its unpaired d electrons, but I also know that there are other metals with unpaired electrons like aluminum that are not ferromagnetic. Is the ...
15 views

### What are the chemical principles behind paper/ink deterioration over time and how do I prevent them? [duplicate]

I have been working on a time capsule for the past few months, in which I decided to not include any electronics (ie: no USB). I am done writing the content of the capsule, but I have some concerns ...
41 views

### Ab Initio and Molecular Orbitals [on hold]

What is the difference between ab initio calculations and molecular orbital theory?
69 views

### Does adding solutes to water alter its triple point? [on hold]

Does adding solutes to water alter its triple point? If yes, how do we find the new temperature and pressure of this point?
47 views

### What does the spherical shape of s-orbital indicate? [closed]

What does the spherical shape of s-orbital indicate? And also of other orbitals
32 views

### A 3:2 molar ratio mixture of FeO and Fe2O3 rates with oxygen to produce a 2:3 molar ratio of FeO and Fe2O3 [closed]

Find the mass in of oxygen gas required per mole of the initial mixture.
30 views

### How to synthesize (4-chloro-2-methylphenoxy)acetic acid from 2-methylphenol? [closed]

How to synthesize (4-chloro-2-methylphenoxy)acetic acid (mPCA) from 2-methylphenol?
39 views

### Why is cyclopropane-1,1-diol stable [on hold]

The reason given me in my book is that it's stable due to steric relief. The answer given on quora said "there is a lot of angle strain." What exactly is steric relief ? Can anyone help me elaborate ...
25 views

### natural staining on wood from human skin

I have a question about the dark staining that occurs on my wooden spectacle frames where they rub constantly with my skin around the ears and nose. Can anyone tell me what is causing this? And could ...