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5
votes
7answers
20k views

The solubility of haloalkanes in water

Haloalkanes aren't very soluble in water because they can't form hydrogen bonds, and the energy required to break hydrogen bonds in water etc is higher than the energy released when new bonds between ...
1
vote
1answer
827 views

How does carbonic acid cause acid rain when Kb of bicarbonate is greater than Ka?

How does carbonic acid cause acid rain when $K_b$ of bicarbonate is greater than $K_a$? Should it not create an alkaline solution? $K_a = 4.8 \times 10^{-11}\ (mol/L)$. $K_b = 2.3 \times 10^{-8}\ (...
2
votes
1answer
827 views

Which process is used to separate Hydrogen and Oxygen from Water?

What's the process called where you can use electricity to separate the oxygen and hydrogen from water? Is it electrolysis? Can it be applied to other liquids?
3
votes
1answer
2k views

Preparation of phenylamine/aniline

This is the procedure I carried out in class: Reduction of nitrobenzene by using tin and $\ce{HCl}$ acid After the completion of the reaction, $\ce{NaOH}$ added to neutralize excess acid and dissolve ...
2
votes
2answers
10k views

Ionizable hydrogen atoms for acids

Given that hydrogen atoms that are attached to a compound must be ionizable for the compound to be an acid, what prevents a hydrogen from being ionized? Is it solubility. If the bond is nonviolent, ...
-2
votes
3answers
2k views

Why are alkali and alkali earth metals indicative of a strong acid? [closed]

Why are alkali and alkali earth metals indicative of a strong acid? Does anyone know why it is so? Or tell me what is indicative of strong acids?
1
vote
3answers
8k views

Why is the reaction between hydroxide and water reversible, when the reaction between oxygen ions and water is not?

Why is the reaction between hydroxide and water reversible, when the reaction between oxygen ions and water is not? And is there a reason why the products of reaction 2) are written separately, ...
16
votes
3answers
980 views

Why doesn't the boiling point of an aqueous solution depend on intermolecular attraction?

I understand that boiling point is a colligative property for aqueous solutions, and that it empirically depends on the mole fraction of the solute, rather than the identity of the solute. I ...
3
votes
1answer
3k views

Vibrational Spectrums of HI, HBr, HF, and HCl

Do you all know of any large graphs for the vibrational spectrums of HI, HBr, HF, and HCl? I need graphs that are large enough to see the spacing between the peaks in the spectra of HCl, HBr, and HI. ...
16
votes
2answers
12k views

Why are vinylic and arylic carbocations highly unstable?

I have checked the internet and read quite a few books, but I still am not able to understand why vinylic and arylic carbocations are highly unstable. What I found while surfing the internet is: For ...
3
votes
2answers
31k views

Distinguish between symmetric and asymmetric molecules with IR

I get increasingly nervous as I get my organic lab course reports. For, I often get asked whether the peak in the IR comes from an asymmetric or symmetric stretch. I've looked at about ten books and ...
1
vote
2answers
2k views

Identify this ion

These are the results I got for my experiment. I'm having trouble interpreting the results. As you should be well aware of, Lithium and Strontium both burn with crimson red when they are placed in a ...
0
votes
1answer
155 views

An example to illustrate the difference between an inversion operation and a twofold rotation

Reading in Atkin's Inorganic Chemistry book, I cam accross: Although an inversion and a twofold rotation may sometimes achieve the same effect, that is not the case in general and the two ...
-2
votes
4answers
143 views

How can one come to know how a catalyst affects a reaction when the reaction and the catalyst is known [closed]

How can I come to know how a catalyst affects a reaction when the reaction and the catalyst used is known. I searched the internet for an answer but could not find one.
0
votes
1answer
202 views

Removing diamonds from a 14 karat gold ring with acid

I have a 14 karat gold ring with diamonds. I want to weaken the metal (to get the diamonds out without damaging them). If I dip the ring in sulfuric acid, will I be able to dissolve the base metal in ...
3
votes
1answer
239 views

Cyclopentadiene/etc. hydrophobicity after nitrogen atom substitution at a double bond?

If I take a compound like cyclopentadiene ($\ce{C5H6}$) and I substitute a nitrogen for a carbon at one of the $\ce{C=C}$ bonds (making a $\ce{C=N}$ bond), how does this typically change the ...
1
vote
1answer
2k views

Internal and external pressure during a gas expansion

There is a solid substance in a rigid cylinder with a piston placed on top such that the distance between the piston and the bottom of the cylinder is essentially zero, and then the substance ...
3
votes
1answer
227 views

How can I protect my skin from KMnO4?

We have national elections coming up in two days, and like every time the election officials will mark people's thumbs with a dab of some purple solution that leaves a brown stain on the skin (and ...
2
votes
2answers
380 views

Atomic coordinates for DNA bases as they appear in a B-form or A-form duplex

Where can I find atomic coordinates for guanosine / cytosine / thymine / adenine (either the ribonucleotide or deoxyribonucleotide bases) where the atoms are configured in the manner we would expect ...
13
votes
7answers
62k views

Why lanthanides and actinides are shown separate from standard Periodic Table layout?

In the standard Periodic Table layout , all the elements up to 56 are in order i.e are in the same layout table. However, lanthanides and actinides are always shown separately from the layout like in ...
18
votes
2answers
7k views

What exactly happened when I added KOH to hydrogen peroxide?

I recently added a potassium hydroxide, $\ce{KOH}$, pellet to a small droplet of hydrogen peroxide (30 %), $\ce{H2O2}$. You could clearly see the potassium hydroxide dissolving in the droplet when ...
1
vote
2answers
475 views

Different techniques of distillations

I know that fractional distillation is used to separate two liquids that are miscible in one another and have close boiling points. However, I am really confused about vacuum and steam distillation - ...
5
votes
1answer
9k views

Reaction between hydrogen peroxide and ozone

What is the reaction mechanism of the reaction: $$\ce{H2O2 + O3 -> H2O + 2O2}$$ I have tried searching this on Google but am not getting good answers.
8
votes
3answers
3k views

How can water catalyse a reaction between iodine and aluminium?

A few drops of water can initiate a reaction between iodine and aluminium. https://www.youtube.com/watch?v=SKSU72-1ERc How can this happen, since iodine is only slightly soluble in water?
6
votes
1answer
5k views

Titration of sulfuric acid with sodium hydroxide

$55.0~\mathrm{mL}$ of $0.250~\mathrm{M}~\ce{NaOH}$ is used to titrate $35.0~\mathrm{ml}$ of $\ce{H2SO4}$. What is the molarity of $\ce{H2SO4}$? I know that the equation for this reaction is: $$\ce{...
2
votes
1answer
323 views

Ideal gas law? implied volume?

Working on a practice exam. The question is A volume of gas contains 0.25 moles of $\ce{CO2}$ 0.30 moles of $\ce{N2}$ 0.15 moles of $\ce{O2}$ What is the partial pressure of $\ce{O2}$ ...
10
votes
2answers
13k views

Why does sodium sulfate have an unusual solubility-temperature curve?

For many salts there are solubility curves as a function of temperature that are smooth (don't have any kinks). Sodium sulfate, however, has a kink in the solubility-T curve at 30 degrees as shown ...
1
vote
1answer
57 views

Atmospheric changes relating to gases

I have the following question: Which of the following would not be used to measure changes in atmospheric gases? i) Satellites ii) Mass Spectrometer iii) Digital Thermometer iv)...
6
votes
3answers
850 views

Understanding Beta Decay

Reading Wikipedia on "Beta Decay" they list the equation of Carbon-14 decaying into N-14. see equation https://en.wikipedia.org/wiki/Beta_decay I presume the 14 refers to total protons and neutrons. ...
2
votes
2answers
186 views

Would decomposing an object into molecules be an environmental problem?

In a thought experiment, a friend proposed to me a machine capable of decomposing any object (e.g., a brick) into its molecules. I'm not a chemist or physicist, but my initial reaction was that this ...
5
votes
2answers
1k views

Why does rearrangement not take place in Wurtz reaction?

The Wurtz reaction is $$\ce{R-X + Na ->[ether] R-R}$$ where $\ce{R}$ is alkyl. But if we take butylchloride with $\ce{Na}$, the product is n-octane and not 3,4-dimethylhexane. I am unable to ...
1
vote
1answer
114 views

What's unique about the most commonly used hetero-cyclic elements? [closed]

I have question about hetero-cycles: Why do we use (the most common hetero-cyclic elements) nitrogen, oxygen, sulfur as hetero compounds most of time?
2
votes
1answer
512 views

Thymolphthalein solubility

I already know that thymolphthalein is soluble in alcohols, very alkaline aqueous solutions, acetone, and propylene glycol methyl ether. My questions are what other solvents dissolve thymolphthalein, ...
7
votes
1answer
42k views

What concentration of sulfur hexafluoride is safe to inhale

I want to do a density demonstration, and I want to inhale helium and sulfur hexafluoride as a fun demonstration. I am open to using any source to purchase from, and money is not an issue (but ...
21
votes
4answers
21k views

How can I clean my lab coat?

Over the course of my studies, my lab coat has absorbed a non-negligible amount of different chemicals, some of them nasty organic polymers, some are more insoluble inorganic compounds like $\ce{Cr2O3}...
7
votes
1answer
2k views

Why does the water in a Powerade bottle tastes a little like Powerade after many refills?

I have a bottle of Powerade and after probably around 20+ refills of water, the new water I put in still tastes/smells a little like Powerade. How does that happen?
4
votes
1answer
812 views

Avoiding snow melting with salt

I've been quite stunned during the last Winter Olympics in Sochi by the following fact. Temperatures were quite high, sometimes 10° Celsius, and the organizers had to do something to prevent the snow ...
3
votes
1answer
338 views

Amphoteric amino acid titration

Glycine $(\ce{NH2CH2COOH})$ is an amino acid with two $\mathrm{p}K_a$ values $(\mathrm{p}K_{a,1}=2.0, \ \ce{COOH};\ \mathrm{p}K_{a,2}=10.0, \ \ce{NH2})$. (a) If $0.01~\mathrm{mol}$ of this amino ...
17
votes
1answer
531 views

Hyperlithiated Carbon Species [closed]

Below is replicated Question 1 from the Final Qualifying Exam of the Australian Chemistry Olympiad, 2004B, here. Question: The theory of promotion-hybridization is quite successful at explaining why ...
1
vote
1answer
989 views

What is/are the product when this reacts with Lucas reagent?

What would be the product(s) if this alcohol reacts with Lucas reagent? Would Methyl shift happen ? I heard that in Groove's process, only primary and secondary alkyl chlorides are formed.
3
votes
2answers
1k views

How can water be electrolysed if it's not ionic compound?

The electrodes have different charges. One is positive ( the cathode ) while one is negative (anode). They will attract the particles in the solution which are charged. Hydrogen to the cathode while ...
2
votes
1answer
1k views

UV radiation on IBr (Radical Substitution)

I came across a radical substitution which Methane reacts with $\ce{IBr}$ to form iodomethane and hydrogen bromide and many more products. I understand the whole process but I don't quite see how the $...
3
votes
2answers
10k views

What happens when C17H35COO-, a soap, reacts with an acidic solution?

My book says that in acidic water, the negative fatty acid ions become fatty acids. However, they did not include a chemical equation to demonstrate this, so I made my own: $$\ce{C17H35COO- (aq) + HCl ...
0
votes
2answers
1k views

How do I clean a silk tie at the knot?

I would like to know how I can clean a silk tie at the knot. I presume it got filthy, over time, due to "fatty" fingers. I am looking for answers either based on 1) good theory or 2) personal ...
0
votes
1answer
51 views

Stationary state mass balance with bypass [closed]

A product should be treated with an air that holds 25% humidity. It is provided with an air with 95% humidity, so it is necessary an absorber to dehumidified with silica gel. The silica gel reduced to ...
2
votes
1answer
542 views

Test for gluten?

I have searched online for 'chemical tests for gluten'; however all the results are about 'home testing kits' (presumably for people with a gluten intolerance). I would like to know if there is a test ...
10
votes
2answers
10k views

Why does water volume decrease when salt is added? [duplicate]

Why does water volume decrease when salt is added? Our teacher asks us in the class but I don't find any strong reason.
10
votes
3answers
3k views

Why weren't the electrons attracted to doubly charged Helium particles in the Rutherford experiment?

I have a chapter and in it there was a topic on the Rutherford experiment. It is written that doubly charged helium particles or alpha particles were thrown towards a very thin gold foil and some of ...
3
votes
1answer
292 views

Condition for formation of azeotropes

Consider a binary azeotropic solution of two volatile components $A, B$. I wanted to try and find out the required concentrations of $A, B$ in the solution in terms of their vapour pressures. I tried ...
3
votes
1answer
2k views

Why is the groundstate electronic degeneracy of monoatomic O(g) 5?

A problem in my Pchem textbook states that the electronic degeneracy of an oxygen atom is 5. My reasoning leads me to believe that the degeneracy is actually 6 (S = 1, L = 1, so (S+1)(L+1) = 6. This ...

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