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3 views

Melting point of crystalline solids

Why crystalline solids have sharp melting points but melting point of amorphous solids vary within a range? Is it cuz the interaction energy is equal btw atoms of crystalline solids so they require ...
0
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0answers
4 views

Crystalline solids

Why crystalline solids are anisotropic whereas amorphous solids are isotonic? Is it because in crystalline solids, x,y and z dimensions vary....but so does in amorphous. Please write as simple as ...
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0answers
8 views

Why thermodynamic state variables of a sytem are only defined at thermodynamic equilibrium and not during any other instant?

As you have read the title so my question is why are thermodynamic variables only meaningful when the thermodynamic system is in thermodynamic equilibrium and is always meaningless in any other case.
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0answers
6 views

How can I convert Potassium Permanganate into a Mn(ii) salt?

I have Potassium Permanganate crystals and I need to make a pure manganese salt in the 2+ oxidation state of Mn. What is the best method?
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0answers
15 views

Alc. KOH and aq. KOH (E2 vs SN2)

So my question is , we know that polar protic solvents tend to decrease the rate of substitution reaction so why does $\ce{aq. KOH}$ favour substitution over elimination whereas $\ce{alc. KOH}$ ...
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1answer
17 views

Why is substitution of halogens to alkanes a chain reaction?

During the propagation step 2, the alkyl radical always react with the halogen molecule according to my textbook. However, isn't the alkyl radical react with the halogen radical formed in the ...
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0answers
6 views

Is Freundlich isotherm valid for high pressure?

Why Freundlich isotherm fails at wide range of high pressure?
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0answers
13 views

Science of soap bubbles

On the web there are tons of different recipes for a solution to make soap bubbles. Most of them use only three ingredients: water dish soap glycerin But their ratios widely change among the sources....
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0answers
18 views

How to model the Belousov-Zhabotinsky (BZ) (in Maple)

I need to model the Belousov-Zhabotinsky reaction (or a different oscillating one). I found out about the Oregonator and the Brusselator reaction and now I want to model them in Maple (or similar ...
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0answers
13 views

How to add components in visual MINTEQ

I need to figure out speciation of a mixture of metal nitrates and chloroplatinic acid. I am using visual MINTEQ to do this. But platinum ion is not there in the visual MINTEQ component list. I need ...
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0answers
19 views

Can sulphuric acid reacting with CoSi2?

Realised sulphuric acid will react with silicon with present of strong alkaline or metallic ion. I am wondering is the same reaction will happen with CoSi2?
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0answers
23 views

Law of equivalence

100 gram mixture of two metals a and b is heated to constant weight of 50 gram containing corresponding oxides of the metals. The equation weight of a and b are 103 and 31 respectively .What is the ...
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0answers
11 views

Can anyone tell me the reaction of acetamide with Conc.H2SO4? [closed]

Can anyone tell me the reaction of acetamide with Conc.H2SO4 ? With mechanism?
3
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1answer
17 views

What is diamagnetic in diamagnetic dilution?

I'm reading a paper where the authors study a peptide solution where each peptide may have two spin labels attached to them. They put the peptides on the surface and study them using a diamond sensor. ...
0
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1answer
14 views

How many significant figures should I report calculating volume concentrations?

Let's say a 300mL soln of $\ce{CuCl_2}$ was diluted to 900mL. I am then asked to calculate the concentration of the new solution. My solution to the problem is as follows: $$M_1 \times V_1 = M_2 \...
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2answers
28 views

Can I mix isopropyl alcohol with an ethanol alcohol gel to increase alcohol concentration?

Can I mix a 99% isopropyl alcohol with a 60% ethanol alcohol gel,( gel is not pure alcohol, a lot of other chemicals in the list) to get a 75% concentration? The reason for mixing is I want to use ...
2
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1answer
26 views

What could be a high school experiment that involves changing a condition to get the highest yield of a certain product?

I am looking for ideas for a chemistry experiment and I am interested in doing one that has to do with the optimization of percentage yields. What could be a high school experiment that involves ...
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0answers
17 views

Latent blood detection with fluorescein

I need help with the reaction between fluorescein and blood in the method of detecting latent blood stains. I find it hard to find any litterateur on this subject. As far as I am concerned, the ...
-2
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0answers
12 views

Answer this using law of equivalence [closed]

100 gram mixture of two metals a and b is heated to constant weight of 50 gram containing corresponding oxides of the metals. The equation weight of a and b are 103 and 31 respectively .What is the ...
0
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3answers
35 views

How many hydrogen bonds can methanol make?

I believe that it can form 2 hydrogen bonds, one with oxygen and the other with hydrogen but a classmate said that oxygen can form 2 hydrogen bonds? Is this true? I can't find anything on google to ...
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0answers
15 views

Why does aluminium have a higher mp than magnesium [duplicate]

The cation size of aluminium is bigger, so why does it have a higher BP and mp?
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0answers
8 views

How molecular structure determines its reactivity patterns? [closed]

How molecular structure determines its reactivity patterns. Explain structure-reactivity relationship with different suitable examples.
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0answers
14 views

Reaction between NaCl and H2CO3 [closed]

If we add sodium chloride to carbonic acid then will it form Sodium carbonate and hydrochloric acid.
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0answers
11 views

How to do a molecule DFT calculation in CRYSTAL?

I'm trying to do DFT calculations for a set of ether solvents so I'm trying one molecule at a time. I took the xyz coordinates from a Chem3D drawing and did geometry optimisation first. After the geom ...
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0answers
20 views

Is polycyanoethene unsaturated or saturated? [closed]

Is polycyanoethene unsaturated or saturated? EDIT: This is not a homework question and i'm not even a student ... I was trying to understand whether a triple C-N bond will make the compound classify ...
-1
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1answer
19 views

Why does stable compounds have less heat of combustion?

My brain somehow doesn't accept that more stable compounds require have less enthalpy. Isn't it like, if a compound is stable, it requires more energy to break the bonds because the compound doesn't ...
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0answers
14 views

Why does percent ionization of a weak acid decrease when the initial weak acid concentration increases?

By the rules of the equibrilium, as the concentration of the acid increases, the reaction will want to dissolve more. So why does the percent ionization of a weak acid or base decrease when the ...
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0answers
20 views

pH of salt solution from strong acid and strong base (aluminum phosphate)

If I add enough anhydrous aluminum phosphate to make a $\pu{0.1M}$ aqueous solution, how could I find the pH, roughly? I know that $\ce{Al^{3+}}$ is able to act as an acid, and phosphate as a base, ...
0
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1answer
16 views

Putting sanitiser in PVC bottles

can I put hand sanitiser in PVC bottles or must the bottles be PET. With the shortage of bottles I am keen to know if a 70% ethanol or isapropyl based sanitiser will distort or soften a PVC bottle in ...
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0answers
32 views

I have 91% isopropyl alcohol & 50% isopropyl alcohol. I want 70% isopropyl alcohol

I have several bottles of 91% isopropyl alcohol, and several of 50%. Due to the situation in my rural area, it seems unlikely I will be able to buy any isopropyl alcohol of any strength, so I want to ...
-1
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0answers
18 views

does oxygen level go up in a closed room if humidity increases in the room? [closed]

i have lit a candle and placed a small sapling near it. Then I put a wet jar over it, will the candle burn a little longer than if a dry jar was put over a lit candle without a plant?
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0answers
14 views

Where does the beta notation come from in the alpha 1,2 beta glycosidic bond (in sucrose)?

I am confused as to where the beta is coming from (in the alpha-1,2-beta glycosidic bond in sucrose). I understand that the alpha is from the anomeric carbon of the glucose, but I don't see how the ...
3
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0answers
38 views

Reaction of alkenes with AlCl3/HCl

I stumbled upon an interesting organic chemistry problem: Previously I thought $\ce{AlCl3}$ would only be used with benzene in acylation and alkylation, but apparently it can also be used in ...
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0answers
15 views

Predict compound structure from NMR spectra and formula? [closed]

Can anyone predict the compound structures from these NMR spectra and formulas? 1: Formula: C14H14 1H NMR: 13C NMR: 2: Formula: C10H10O2 1H NMR: 13C NMR:
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0answers
18 views

An element X2- has the same configuration as the phosphide ion. Identify the element X [closed]

An element forms an ion $\ce{X^{2-}}$ that has the same configuration as the phosphide ion. Identify the element $\ce{X}$. Can someone explain, in detail, how I would work this out?
4
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2answers
205 views

What software was used to create these organic reaction scheme figures?

I am aware that software such as ChemDraw, ChemDoodle or MarvinSketch can be used to draw skeletal formulas and the like. But what can I use to draw (in a similarly professional way) reaction schemes, ...
6
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4answers
467 views

Why is solubility often listed as a chemical property? Isn't the action of dissolving just a physical change?

I am making a list of basic physical vs chemical properties. I have been taught that when salt dissolves in water it is simply a special kind of mixture called a solution. I have been taught that ...
-1
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1answer
16 views

pKA versus amount of base Question

so I am stuck on a problem, which basically asks what the concentration of the base will be given the high pKa. The answer is that the higher the pKa, the lower the concentration of the base, since ...
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3answers
37 views

Activities and molar concentrations

I would be really happy if someone would clarify the term "chemical activity" and its implications for me, and also how it is related to the concept of molar concentration. My textbook fails at ...
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2answers
37 views

T∆S implies that heat flows which way?

From Schroeder's Introduction to Thermal Physics. Parts $(a)$ and $(b)$ are quite simple, and we find that $ \Delta H =-2808\ \mathrm{kJ}$ and $\Delta G =-2879\ \mathrm{kJ}$, so by $\Delta G = \Delta ...
9
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3answers
429 views

What chemical reactions could ancient people use to propel projectiles?

Are there reactions other than burning of gunpowder that ancient people could perform that would produce gas from non gaseous substances, so that it could have been used for propulsion of projectiles ...
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2answers
60 views

What will happen if I trap an ozone producing device inside a small airtight area?

I'm currently building a UVC light, and right now I'm working on figuring out how to place it in an aluminum reflector housing to cast the beam of light effectively. It's creating a lot of ozone, and ...
0
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0answers
29 views

Vapour Pressure of A Solution

I study in class 12, and have a doubt in vapour pressure that my school teacher and my friends are not able to clarify. My doubt is the reason why the partial vapour pressure of each individual ...
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0answers
17 views

How many grams of sodium bicarbonate, Na₂CO₃, reacting with excess barium sulfate, would be required to produce 85g of barium carbonate? [closed]

How many grams of sodium bicarbonate, Na₂CO₃, reacting with excess barium sulfate, would be required to produce 85g of barium carbonate? Na₂CO₃ + BaSO₄ → BaCO₃ + Na₂SO₄ I am trying to understand ...
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0answers
20 views

Indicators used in Titration [duplicate]

I want to know everything in detail about Indicators used in titrations, their structure,pH range. Please suggest me a book for it.
0
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1answer
38 views

Nernst equation and equilibrium

I am currently stuyding electrochemistry, and recently I've stumbled upon a problem where one is supposed to calculate the concentration of Fe3+ ions after a solution containing Fe2+ was titrated ...
0
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0answers
41 views

Are these two reactions the same?

I read the book an it said when $\ce{NH4Cl}$ dissolves in the water, the reaction of $\ce{NH4+}$ will be $$\ce{NH4+ <=> NH3 + H+},$$ but instead, the first reaction came to my mind was $$\ce{...
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0answers
24 views

Is the first step of most the accepted mechanism of Perkin's reaction correct?

If I am not wrong this is the most accepted mechanism of perkin's reaction: In the first step, is the acetate ion basic enough to abstract proton from acetic anhydride? If yes, I have a counter ...
0
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1answer
21 views

Reactivity of Ammonium

I was going through some displacement reactions when this struck me: What is the position of the ammonium cation in the metal reactivity series? I can find other positive ions like carbon and ...

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