All Questions
37,125
questions
3
votes
1answer
457 views
How are electronic configurations including hybrid orbitals notated?
I know the general scheme for notating electronic configurations is (with s and p orbitals) [noble gas core]nsel.$n$pel. etc., where $n$ is the principal quantum number and el. is the number of ...
6
votes
1answer
17k views
Why exception is noted in the solubility of lead salts?
There are many exception in the solubility of lead salts like:
Lead sulfate is insoluble in cold water whereas most of the sulfates are soluble in cold water.
Lead chloride is also insoluble in cold ...
10
votes
2answers
9k views
Should bromine water be called a solution?
Bromine water is a reagent which is used to test for unsaturation in organic compound. It is $2.8~\%$ bromine in water. In many places, it is refer to as bromine solution.
But it is observed that ...
0
votes
2answers
8k views
Abnormal deviation of CO2 from ideal gas behaviour [closed]
Why does carbon dioxide show larger abnormal deviation from ideal gas behaviour than other gases. Why does carbon dioxide first show negative deviation and then positive?
4
votes
1answer
1k views
Stability of alkenes by hyper conjugation
I have learnt that for carbocations, electrons are delocalized from the $\ce{C-H}$ $\sigma$-bond to the empty p-orbital of carbon.
Moreover, alkenes are stabilized by the delocalization of electron ...
3
votes
4answers
513 views
Thermodynamics entropy and temperature
In thermodynamics, whenever heat is released from the system to the surroundings, temperature of surroundings remains unchanged but entropy increases. But entropy is a function of temperature. How is ...
3
votes
2answers
2k views
Different possible Lewis structures of peroxymonosulfate anion
I was trying to draw the Lewis structure of $\ce{HSO5-}$ (peroxymonosulfate), so I came up the structure on the left that satisfies the octet rule. Then, I saw that the correct structure is the one on ...
4
votes
2answers
3k views
Do electron donating groups make a molecule nucleophilic?
Do electron donating groups make a molecule nucleophilic?
One group, the alkyl group in this example, is electron donating in $\ce{CH3CH2O-}$. Will the molecule be nucleophlic?
4
votes
0answers
354 views
What are the dangers of melting HDPE and silicone? Is it even possible?
I've searched the internet and couldn't find a specific answer.
There doesn't seem to be a single recycling company that takes empty silicone tubes (also know as mastic tubes) and recycles them. As a ...
10
votes
3answers
3k views
Why is diene more reactive than alkene?
The chemical reduction of 1,3-butadiene with sodium in alcohol gives mainly the 1,4-addition product that is but-2-ene.
Under these condition the isolated double bond are not reduced. This suggest ...
2
votes
1answer
63 views
1
vote
1answer
71 views
Is there such thing as too much fermentation
When you make a wine the more you age it the better the taste. But is there such a thing as too much fermentation where it makes the wine taste worse? If not is there a time where fermentation doesn't ...
2
votes
1answer
1k views
Three general questions in silanization of a glass surface
For silanization, I put a glass slide horizontally and pour the silan solution on it to cover the glass surface. Then I leave it for a specific time and then wash with water and acetone.
I have ...
4
votes
0answers
1k views
Cat litter crystals causing toxic smell upon rubbing and pouring out of the package, safe?
I am under-educated in terms of chemistry hence the question and assumptions.
Basically, for our cats, we are using what seems to be the latest scientific achievement in litter sand - the litter ...
3
votes
1answer
718 views
Stereoisomerism in 1,2-cyclobutanediol
For 1,2-cyclobutanediol, it's given in my book that it has 3 stereo isomers.
Here's the passage:
My questions:
How can it have stereo-isomers?
What will the meso compounds look like?
0
votes
2answers
485 views
overall energy and the boiling point
i need help with the fractional distillation method of a couple of substances at least more than two substances , just like air actually what am i looking for is that why do substances in air with a ...
4
votes
1answer
4k views
Is FeS2 both an ionic and covalent compound? [duplicate]
Iron (II) disulfide. Iron pyrite. Fool's gold to some. But what bond does it fall under? It could possibly be used for both?
This would give a deeper understanding into other like examples, where ...
-1
votes
2answers
2k views
boiling point and distillation relation
i need help with the fractional distillation method of a couple of substances at least more than two substances , just like air
actually what am i looking for is that why do substances in air with a ...
2
votes
0answers
279 views
Why we have mass of adsorbent in Freundlich equation?
In Freundlich equation why we have $m$ the mass of adsorbent. I mean it is surface chemistry and on the surface of adsorbent the adsorption takes place so why we have mass of adsorbent in that ...
0
votes
1answer
80 views
Need to chemically heat water
I have a holding tank on rv, non potable water that I need to heat up to drain . I live in northern Alberta, so the average temperatures are -20. I don't want to wreck anything or gas myself out. I am ...
3
votes
1answer
609 views
Ostwald Law of dilution makes no sense
According to wikipedia
the Ostwald's dilution law says that for a weak acid
$K_{d}={\cfrac {[A^{+}][B^{-}]}{[AB]}}={\frac {\alpha ^{2}}{1-\alpha }}\cdot c_{0}$
when I read the derivation of it ,I ...
0
votes
1answer
89 views
Experimenting with electrochromic prussian blue
I am attempting to preform this experiment. Chemistry isn't really my cup of tea, so I have a couple questions.
The instructions say to provide 40µA per cm2, where does that number come from?
The ...
1
vote
0answers
46 views
Sulfur atomic absorption
Would the atomic absorption from FAA for Sulfur be from 3s2 -> 3p4 or 3p4 -> 4s0?
I think according to the electronic partition function, there would be zero electrons in the 4s0 state at the ...
2
votes
1answer
116 views
About how much carbon monoxide is produced in these two different reations?
The U.S. Department of Agriculture produces a gas cartridge to poison subterranean rodents. The product is provided as a cardboard tube sealed at one end and then loaded with a mixture of 144.6 grams ...
3
votes
2answers
1k views
Absolute configuration in stereochemistry: R/S nomenclature
I have all the rules of Fischer projections figured out.
But, when the problem asks for finding the configuration of a molecule with 1 chiral carbon and in a Fischer projection form, do we need first ...
10
votes
1answer
701 views
Stability of isomers of N4O
I have googled and found that the structure of $\ce{N4O}$ is linear with a positive and negative charge on 2 nitrogen atoms. But, the following structure seems more stable because it fulfils octet for ...
5
votes
1answer
338 views
Why was the Deville process of Alumina production given up in favor of the Bayer process?
I guess this is a sort of historical question. The DeVille process seems fairly simple. Does anybody know the history or practical reasons for the switch?
5
votes
1answer
13k views
Why is the Friedel-Crafts alkylation of nitrobenzene disfavoured?
Suggest a synthetic route to m-nitrotoluene, starting from benzene.
The conversion can be achieved in two ways:
$\hspace{10 mm}$
or:
However, the first route is not possible as the Friedel-Crafts ...
0
votes
1answer
95 views
Aren't unit cell and the relevant crystal similar?
"A crystal is formed by a large number of repetitions of basic pattern of particles in space.
The basic structural unit which when repeated in three spatial directions generates the crystal ...
3
votes
0answers
66 views
Detect a baked diamond?
Diamond suppliers often "bake" stones. This causes them to expel yellow-causing nitrogen and become white, but also makes them more brittle. A baked diamond can often be recognized by its unnatural ...
1
vote
1answer
3k views
How to calculate the sufficient ratio of acid and corresponding base of the indicator that allows to clearly observe the endpoint of a titration?
Ram can see the purple colour of an acidic indicator below pH = 5.5 only and the blue colour only above pH = 8.5. How many times that of acidic form must the concentration of the basic form at least ...
4
votes
1answer
1k views
How to distinguish between carbon-carbon double bond lengths?
Which of the following compounds should have the longest carbon-carbon double bond?
$\ce{CH2=C=CH2}$
$\ce{H3C-CH=CH2}$
$\ce{(H3C)3-C-CH=CH2}$
$\ce{(H3C)2C=CH2}$
I know that single ...
19
votes
4answers
11k views
Addition of HOBr across C=C
Source: Carey Advanced Organic Chemistry B, problem 4.1 b
Looking for interesting problems about addition to C=C, I came across this in the back of Carey. It looks like a simple addition across ...
3
votes
1answer
151 views
Why does dry boiling discolor steel cookware?
I have a stainless steel kettle that I let boil dry. That is, I left it on a hot coil burner with nothing in it, and noticed a few minutes later that the bottom was red hot and smoking. To make ...
-4
votes
1answer
53 views
Is conversion of L-glutamate to 6-phospho-D-gluconate a feasible reaction? [closed]
I want to know whether a reaction is feasible or not. Can L-Glutamate ($\ce{C5H9NO4}$) be converted to 6-Phospho-D-gluconate ($\ce{C6H13O10P}$) or vice versa in one step?
10
votes
2answers
7k views
What is the chemical test for identification of benzophenone?
How to identify that a unknown compound is benzophenone?
My working:-
First I added 2,4- DNP(2,4-Dinitrophenyl hydrazine) to the compound. Yellow-orange crystals were formed which indicated presence ...
3
votes
2answers
4k views
Does adding ice to sparkling mineral water extend the 'fizziness' of the solution before the drink goes flat?
To my understanding the carbonated beverage loses its $\ce{CO2}$ content as gas bubbles which gives the drink its 'fizziness'. The loss of $\ce{CO2}$ occurs due to the low solubility of carbonic acid ...
3
votes
1answer
1k views
Compounds that release carbon dioxide [closed]
What are some compounds that release carbon dioxide when heated, hydrated, or reacted with sodium, aluminum, silicon, or iron?
3
votes
0answers
179 views
What acid can remove Calcium in Ca2SiO4 to leave SiO2 (mostly)
What acid can remove calcium in $\ce{Ca2SiO4}$ to leave $\ce{SiO2}$ (mostly)?
It seems that calcium silicate is stable in most acids, but I need to etch it and leave only silica (mostly).
10
votes
1answer
616 views
Is lithium L-threonate a potential brain medicine?
Lithium ions have known neuroprotective qualities. That would explain its therapeutic benefit in some mental disorders. It is also well known that lithium carbonate must be taken in toxic doses to get ...
1
vote
1answer
980 views
Galvanic corrosion: Copper, iron and aluminum in an automotive cooling system
I am building a small copper heat exchanger I am going to plumb into my coolant system. I'm afraid that the copper will corrode my aluminum radiator or iron engine through galvanic action via the ...
1
vote
0answers
315 views
van't hoff factor
Basically I was doing a freezing point depression question where enough information was given to calculate the van't Hoff factor(i) which was 1.86. Anyways the question was asking to calculate the ...
6
votes
1answer
534 views
Diastereoisomer of quinic acid and its proton NMR?
Question:
Quinic acid, A, has the gross structure shown below:
(i) Draw all the possible diastereoisomers of A and indicate which are chiral.
(ii) Quinic acid is optically active and ...
3
votes
2answers
100 views
How can a sample that is in two different states be at a uniform temperature?
In my chemistry course, the professor has discussed how a sample that contains both solid and liquid water would be at 0 degrees Celsius no matter what the proportion of solid to liquid water is. I ...
1
vote
0answers
384 views
Is the reaction between powdered soap and water exothermic?
I have done a fair share of hand washing using powdered soaps and in the first few seconds after mixing the soap with water, I have in most cases felt a subtle warmth in my hands. Is it that the ...
3
votes
0answers
117 views
Coordinates for molecules except cartesian and zmatrix
Every program in theoretical chemistry that I know uses different ways of writing their input. The same holds true for writing the geometry of the molecules of interest. But they can all be reduced to ...
11
votes
3answers
3k views
Does a reaction have to have a rate determining step?
I am a bit confused about the concept of the rate determining step. From what I understand, a step in a reaction is the RDS if it meets the following requirements:
It is the slowest step in a ...
8
votes
1answer
294 views
How to explain this acid-catalysed acetal rearrangement mechanistically?
I have spotted a protecting acetal group and thought this would undergo hydrolysis … My working is such:
But I cannot get to the desired isomer. Could someone please help? (Diagrams would be very ...
14
votes
1answer
868 views
Why was Lawrencium's symbol changed?
The initial proposal by Lawrence Berkeley National Laboratory scientists for naming element 103 was "Lawrencium" with the symbol "Lw", However, while IUPAC accepted the name "Lawrencium" for the ...
15
votes
3answers
13k views
Why don't free radicals undergo rearrangement like carbocation/carbonium ions do?
Why don't free radicals and carbanions undergo rearrangement like carbocation/carbonium ions undergo in a reaction?