The study of chemical systems using the laws and concepts of physics. This usually requires the techniques of thermodynamics, statistical mechanics and quantum mechanics.

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Purity of precipitate in selective precipitation

An aqueous effluent contains 12 M Cd2+ and 10 M Mg2+ as solution of nitrates. Current practice is use NaOH to selectively precipitate the metals. (a) Is it feasible to get 0 Cd impurities in Mg ppt ...
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1answer
19 views

Does the catalyst alter the Potential energy Surface?

Catalyst provides alternative pathway to the reactants. Does it also mean that the potential energy surface is altered?
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1answer
23 views

What are the triple point pressure and temperature for pure cyclohexane?

Here is a video that demonstrates the interesting nature of the triple point of cyclohexane, so I tried researching on the internet for a phase diagram, but only found data from a manufacture where ...
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0answers
23 views

Gibbs Free Energy, Entropy and Enthalpy [on hold]

The Gibbs energy as a function of T for a certain substance can be expressed as: G = aT + b + T-1 , where a and b are constant and T is the absolute temperature. a) What is the entropy of this ...
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5 views

What is the heat of dissolution of sodium acetate trihydate?

Is the reaction endothermic since its crystallization is exothermic?
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2answers
1k views

Why is snow white?

I know that this is a rather ambiguous question; but my question is, whenever we take water and freeze it in the freezer, it still tends to stay clear. Since snow is just frozen water, why is it ...
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1answer
22 views

Which is more: dissociated ions in water or undissociated? [on hold]

While studying equilibrium we get to know that there are $1*10^{-7} \ce{~~OH-}$ and $\ce{H+}$ ions in pure water. However, I think there are more undissociated molecules.
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1answer
258 views

Why is the specific heat of water high?

How is the specific heat of water so high? I was reading the hyperphysics article on it but could not understand it properly.
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1answer
76 views

Volatile nature due to Hydrogen bonding

Why does intramolecular hydrogen bonding make an organic (or possibly inorganic as well(?)) compound volatile. What I think is that it might be due to decrease in the solubility of the compound as ...
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2answers
27 views

What is the difference between K and Kp in the equilibrium equation?

In this equilibrium equation, $$K = K_p\cdot (\mathcal{R}T)^{-\Delta n}$$ what does $K$ represent in comparison to $K_p$? It seems to me that they'd both be equilibrium constants, but how are they ...
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1answer
19 views

compression set of tin catalyzed silicone better than platinum?

Platinum silicone is more dimensionaly stable, it shrinks less when it cures. However, i just need silicone which has good compression set (small change by compression), and perhaps, once they are ...
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1answer
1k views

Is the atom the smallest particle, which takes part in chemical reactions?

According to modern atomic theory, the atom is the smallest particle which can take part in a chemical reaction. But during the formation of hydronium ion, $\ce{H+}$ ion reacts with $\ce{H2O}$ to form ...
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28 views

What is meant by miller indices? [closed]

What is meant by miller indices of a crystal? I need detailed explanation about miller indices of different types of crystals.
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2answers
26 views

How do I determine if a process is reversible without numeric information?

How do I determine if a process is reversible without numeric information? It would be nice to know how to determine whether a process is reversible in order to solve problems LIKE this one: A ...
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0answers
44 views

How to calculate the rate constant at a certain temperature, given first order rate constants at different temperatures? [closed]

I have this problem that I am trying to study for my test: A reaction has first order rate constants of $4.82 \cdot 10^{-5}~\mathrm{s^{-1}}$ at $25~^\circ\mathrm{C}$ and $1.41 \cdot ...
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1answer
33 views

Deriving The Triple Point Temperature and Pressure as the following expression

$ΔH_{fus}, ΔH_{vap}, ΔH_{sub}$, as well as ($Tl,Pl$) and ($Ts,Ps$), which corresponds to the temperature and vapor pressure of liquid and solid phrase. My strategies is to use the Clausius-Clapeyron ...
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2answers
61 views

What stopper will stop HCl fumes?

The local hardware stores actually sell chemicals in recycled beer bottles with plastic stoppers as lids. The bottle of hydrochloric acid I bought is clearly losing gas to diffusion through the ...
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0answers
28 views

Why does hot water make more bubbles than cold water when i wash my hands? [closed]

I have observed this many times. Is there a reason or just a coincidence?
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0answers
12 views

Could someone explain the phenomenon of Dynamic heat capacity and fictive temperature for thermoplastics?

Could someone explain the phenomenon of Dynamic heat capacity and fictive temperature for thermoplastics in polymers?
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1answer
88 views

What is the actual reason behind PCl₅ existing as an ionic solid?

Why does $\ce{PCl_5}$ exists in the solid state as $\ce{[PCl_6]^{-}[PCl_4]^{+}}$? What is the problem with it that it doesn't exist in its original form in solid state? Like why isn't it just ...
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1answer
42 views

Whose concentration is more 1 molar or 1 molal?

I was reading about concentration terms like molarity, molality, etc. and then I came across a question: which concentration is more: 1M(molar) of solute x dissolved in water vs. 1m(molal) of solute ...
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2answers
155 views

Where did all the elements come from? [duplicate]

I heard somewhere (I think is was a show called "How The Universe Works") that the big bang was the result of a hydrogen atom and a helium atom. Is this true? If so, where did all the other elements ...
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0answers
24 views

How do things heat one another? [duplicate]

For example, how does a gas stove heat a metal pot? A combustion reaction between the gas and the air takes place, and this releases energy due to new chemical bonds being formed. Do the atoms in ...
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2answers
29 views

Why is the volume in this compress gas cylinder constant throughout?

I am stuck on this gas question and its really stressing me out. A compressed cylinder of gas contains $2.25 \cdot 10^3~\mathrm{g}$ of $\ce{N2}$ gas at a pressure of $4.25 \cdot ...
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1answer
33 views

How can I calculate molality from molarity?

How can we determine the boiling point of 1 molar aqueous solution (density 1.06 g per ml) of KBr? If I use the colligative property formula than I require molality instead of molarity. Here the ...
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Weighted Drilling Fluid Comparison with CaCl₂

I asked a question previously, and the answer was quite illuminating. The answer ushered me forth in a direction that finally made sense. I ended up finding this website, ...
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957 views

Salts that are more hydrophilic than NaCl

What other, rather easy to obtain, salts are more hydrophilic than $\ce{NaCl}$? Is there a hydrophilic scale for substances like the Mohs scale of mineral hardness?
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2answers
34 views

Can powdered beta-tin be made from raising the temperature of alpha-tin?

When white tin ($\beta$-tin) is exposed to temperature below 13.2$^o$ C it creates the allotrope of gray ($\alpha$-tin), a gray amorphous powder. My question is that once you have the powdered gray ...
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0answers
34 views

Soy milk + coffee ->?

I am not sure if this is a chemistry or a physics question so if I am in the wrong place I would appreciate a heads up :) I noticed when I poured my soy milk (which I shook as per the directions on ...
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1answer
22 views

How do I calculate the pressure of a known liquid in a sealed container heated above boiling point?

Wasn't sure if this was more of a physics of a chemistry question. If I have water in a sealed container heated to say 150 degrees, how do I determine the amount of pressure being generated in the ...
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1answer
47 views

Is there a relationship between bond strength and polarity?

I believe that a more polar bond would be stronger, since it would be similar to an ionic bond. However, this seems to be wrong when applied to the study of acidity of some compounds.
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17 views

Interpreting X-ray diffraction data

So I've got my data for some x-ray crystals of small molecules of Ag, Cu,... I was curios to know what the best way to determine what type of lattice each of these atoms may have?
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1answer
17 views

In monomolecular how can reactant experience collision?

Molecularity means no molecules which experience collision with each other taking part in reaction. So how it is possible that in monomolecular reaction Only one reactant experiences collision?
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21 views

Chemical potential of mixtures

I feel that there are very few textbooks that treat the chemical potential of mixtures in an understandable clear way, which is why I wanted to ask here about certain things. Although I do not have a ...
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1answer
29 views

Entropy - Negligible?

In electrochemistry, the Nernst equation tells us the cell potential for non-standard conditions. I read that the factor $\frac{-RT}{nF}\ln{Q}$ accounts for difference in cell potential due to ...
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2answers
30 views

Rate constant and Michaelis Menten

Please consider the following figure of a concentration over time (msec) diagram with variables for an enzyme, a substrate bound enzyme and a product. Recall that $\ce{E + S \leftrightharpoons ES ...
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1answer
46 views

Is there a difference between Joule coefficient and Joule-Thomson coefficient?

Is there a difference between the Joule coefficient and the Joule-Thomson coefficient? Also, I am having a hard time understanding what they mean.
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1answer
36 views

Volume Of A Nitric Oxide Molecule [closed]

So I was wondering what would be the best way to calculate a rough estimate for size of a Nitric Oxide molecule to use in comparison to a box. I was thinking volume would be the best method, but ...
2
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1answer
17 views

Oxide surfaces develop a charge in H2O. Do we have any, even vague, handle on how long does an indivdual charge last on avg. before being neutralised?

We often know, from e.g. titration experiments, what the average surface charge density of a surface is. How do these charges vary over both time and space (i.e. dynamics)? I have been unable to find ...
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1answer
29 views

Can an emulsion be emulsified?

Can clusters of an emulsion be emulsified into another emulsion? If so is there any common product or natural substance that would have such a structure? Finally is there a name for this? I looked ...
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9answers
637 views

How do I excel in Chemistry? [closed]

I wanted to ask an online group of experts/community about how I could improve in chemistry. I study in class X currently and don't get very good grades. Most of the time its a B or C. I have to ...
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0answers
15 views

Which solvent is good for using SU-8 particle in Optical tweezers?

I'm studying Optical tweezers. I've used Polystyrene for samples. Nowadays, I've got SU-8 pillar. I wanna use that for sample, but its density is heavier than water. I can't use that. So I wanna know ...
9
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1answer
107 views

Can magnetic fields affect a chemical reaction?

This question was asked recently in an interview and I just said that "Yeah, like if the reaction involves ions or paramagnetic species". But the interviewer went on and asked me to elaborate on HOW ...
3
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1answer
43 views

Reaction Kinetics and Stoichiometry — Mass conservation

This question has been bothering me for some time, and I can't seem to find a good answer online. Say I have four chemical species $\ce{A}$, $\ce{B}$, $\ce{C}$, $\ce{D}$, and these four react in the ...
10
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1answer
1k views

Why is beryllium transparent to x-rays?

Beryllium has other fancy applications. It is transparent to x-rays, so it's used in the windows of x-ray tubes, which need to be strong enough to hold a perfect vacuum, yet thin enough to let the ...
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2answers
35 views

Predicting rate equations from data

I am having trouble wit the following question on my problem sheet: "The reaction $\ce{Br- + ClO^- \to BrO^- + Cl^-}$ occurs with a rate constant of $\text{0.35 dm}^3 \text{mol}^{-1} \text{s}^{-1}$ ...
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0answers
17 views

The Workings of Pulse-Height Discrimination

Pulse-height discrimination is a common technique to filter out unwanted background signals from the analytical signals. But how exactly does it work? The analytical signals are not continuously ...
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2answers
41 views

Second order reaction half life equation?

For the reaction: $$2A\to p$$ The rate, $v$ may be given as: $$v=-\frac12\frac{d[A]}{dt}=k[A]^2$$ Correct? Integrating this gives: $$-\frac12\int_{[A]_0}^{[A]}\frac{d[A]}{[A]^2}=k\int_0^tdt$$ ...
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1answer
32 views

Does the speed of an ion affect the current that can flow through a solution?

Typically, when a cathode and anode are inserted into a solution that allows current to flow, the ions are moving with a certain kinetic energy. If the ions were to gain kinetic energy (through ...