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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How do I calculate the density of propane assuming an ideal gas?

Assuming an ideal gas, calculate the density in $\mathrm{g/cm^3}$ of propane, $\ce{C3H8}$ at $0.000~^\circ\mathrm{C}$ and $1.000~\mathrm{atm}$. (3 significant figures) I have figured out that I ...
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1answer
17 views

Molality of solution having more than one solute?

So here is my question, Question: A water sample contains 9.5% $\mathrm{MgCl_2}$ and 11.7% $\mathrm{NaCl}$ (by weight). Assuming 80% ionization of each salt. Boiling point of water will be ...
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1answer
33 views

How to calculate the heat of dissolution from a calorimeter experiment?

A $1.50~\mathrm{g}$ sample of $\ce{KCl}$ is added to $35.0~\mathrm{g}$ $\ce{H2O}$ in a Styrofoam cup and stirred until dissolved. The temperature of the solution drops from $24.8$ to ...
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1answer
21 views

DFT Calculations, Atomic Ionization Potentials — Which Exchange-Correlation Functional to Use, to Preserve Koopmans Theorem?

I have a program which can perform density-functional calculations for atoms, given a density functional. Of course the simplest form of exchange potential to use is one relevant for a uniform ...
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2answers
99 views

A misunderstanding about the energy profile of reactions with a catalyst involved

All of us are aware of the importance of the catalysts in bio-chemistry. For a high school learner like me, catalysts ,and therefore, enzymes play a bridge-like role that connect high school bio to ...
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1answer
35 views

Percent composition, maybe?

I've attempted to solve this problem with percent composition, but it says the answer is wrong. Is it a PV=nRT problem, and if so, can I use the units as they are given? A 0.02867 g sample of gas ...
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0answers
11 views

Debye Length and Ethanolic Solution

What is the Debye length of a conducting metal oxide particle immersed in a $28.7\text{mM}$ ethanolic solution of $\text{CaSO}_{4}$ at $47^{\circ}C$? Assume a dielectric constant of the medium of ...
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0answers
15 views

What is the potential of the given Ag electrode? [on hold]

What is the potential of a $\ce{Ag}$ electrode (immersed in a pH 4 solution containing $4.46\ \ce{Ag}^{+}$) vs. a $\ce{Ag}/\text{AgCl}$ reference electrode? I think we use the Nernst equation for ...
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0answers
8 views

Flux and Surface Coverage

How long will it take for a surface to be covered by $0.3ML$ of $\text{CO}$ in a 2-fold coordination, assuming that the flux of the $\text{CO}$ gas is $10^{14}\text{molecules}/(m^{2}s)$? I am ...
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0answers
5 views

Surface Area from Thermogravimetric Analysis (TGA)

The adsorption of $\text{H}_{2}\text{S}$ on $\text{Ni}$ nanoparticles is shown by TGA to give a mass gain of $200\mu g$ at $500^{\circ} C$ due to the deposition of $\text{S}$ on every second ...
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1answer
19 views

Average Size of Cubic Crystals [on hold]

The total area of $0.5$g sample of KCl powder is measured to be $1620$cm$^{2}$. If the powder consists of tiny cubic crystals, what is the average size of these crystals? I'm studying for a physical ...
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2answers
49 views

Confused about parity of atom and chirality

OK. I'm working in computational chemistry and the problem that bothers me is: Given a molecule, I know that it has a central asymmetric atom with some parity which is either "Anticlockwise" or ...
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0answers
17 views

How to calculate concentration of trace metal? [on hold]

How to calculate concentration of heavy metal in ppm using calibration curve and standard addition method?
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2answers
65 views

Where does the Fe(III) ion go?

Iron(II)Sulphate solution is added to a test-tube. Following this, potassium manganate solution is added gradually to the test-tube as well. The observation seen is that the green solution turns pink ...
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0answers
14 views

Good resource for chemical equivalence

I need a good resource that explains the concept of chemical equivalence and its various application in physical chemistry. I have not found anything worthwhile from a Google search.
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0answers
26 views

Calculate the percentage of ZnO and Fe_2O_3 [closed]

Calamine, which is used for relief of skin irritations, is a mixture of zinc and iron oxides. A $1.022-\ce{g}$ sample of dried calamine was dissolved in acid and diluted to $250.0 \,\ce{ml}$. ...
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0answers
27 views

Determine the free energy when you have present in a 2.00 L flask: 8.0 atm pressure of NH3 (g) and 4.0 atm pressure of N2(g)

I don't know what to do to find the of free energy when you have present in a 2.00 L flask: 8.0 atm pressure of NH3 (g) and 4.0 atm pressure of N2(g). This is the table given: Cu(s) ΔHf° (kJ/mol) = ...
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2answers
49 views

Symmetry representations for CH3CN

Can anybody share the symmetry labels for acetonitrile ($\ce{CH3CN}$), please? I mean I to assign the symmetry labels to orbitals of acetonitrile
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23 views

Resource Request: Applications of (Relatively) Advanced Physics to Chemistry [closed]

I have been studying various areas of physics including quantum mechanics, quantum field theory, etc. Most of these physics texts have done a good job presenting the theories but they are sorely ...
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0answers
27 views

What is the heat required for a fluorocarbon to be converted from a liquid to a gas? [closed]

The fluorocarbon compound $\ce{C2Cl3F3}$ has a normal boiling point of $47.6~^\circ\mathrm{C}$. The specific heats of $\ce{C2Cl3F3(l)}$ and $\ce{C2Cl3F3(g)}$ are $0.91~\mathrm{J/g⋅K}$ and ...
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2answers
97 views

Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode

I've run into trouble on this question Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode $\ce{Ag(s)|AgCl(s)|Cl-}$. ...
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1answer
9 views

Quick Stoich & Gasses

I have a quick question in Stoich and Gasses, I however could not get any far, any answer will be appreciated. Thank You. A sample of $\ce{Pb(NO3)2}$ is heated, yielding $\ce{O2, NO2\ gas,\ and\ ...
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2answers
61 views

What is the mathematical foundation for the probabilistic nature of chemistry?

Is this best answered through quantum theory, Boltzmann statistics, or what? For example, in a reaction energy diagram, only some of the reactants go over to the side of the products, and then get ...
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300 views

What Causes there to be a Maximum Amount of Salt which can be Dissolved in Water?

When you add salt to water and stir, after a while the salt will no longer dissolve. Why is this?
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34 views

Gas Stoichiometry & Ideal Gas Law

I need a little help with one of the problems below. Any help on the problem below will be appreciated. I don't want to sound like an idiot, I will also provide my work. Solid $\ce{NaHCO3}$ ...
7
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1answer
126 views

Why doesn't limestone thermally decompose instead of turning to marble?

When limestone is buried and put under intense heat and pressure, why does it turn to marble instead of thermally decomposing into calcium oxide and carbon dioxide?
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0answers
15 views

Does product induced poisoning qualify as a rate limiting step?

I have a question about whether a particular situation qualifies as a rate limiting step. I have a catalyst that under normal conditions gets poisoned when products accumulate on the catalyst surface. ...
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2answers
228 views

Where does the molar mass difference between N₂ and CO come from?

The molar masses of $\ce{N2}$ is 28.0134 g/mol, for $\ce{CO}$ it's 28.0101 g/mol (WolframAlpha computation). Of course, they do have the same mass in atomic units (28). My question is, where does ...
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1answer
52 views

Why is water transparent?

Some substances like Copper Sulfate for example have vivid colors. But why is water transparent? Does it not emit any visual light from the electromagnetic spectrum?
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1answer
21 views

What will happen to the entropy and free energy of the gasses when the partition is removed?

Consider a container of volume $ 5.0$ L that is divided into two compartments of equal size. In the left compartment there is nitrogen at $1.0$ $atm$ and $25 °C$; in the right ...
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1answer
24 views

How significant is air decomposition on NOₓ formation?

How significant is $\ce{NO$_x$}$ formation from $\ce{O2}$ (reactant) and $\ce{N2}$ decomposition from simply heating the two as opposed to from $\ce{CO2}$, $\ce{H2O}$, (and $\ce{N2}$) dissociation? In ...
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1answer
37 views

What conditions can cause a material to exist as a gas?

So my question is, how can something exist a gas. Is it when the pressure exerted by the gas is greater than the atmospheric pressure, then it is a gas? And also how do manometers work, how can you ...
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1answer
26 views

Stuck with derivation of the integrated rate equation for a pseudo first order equilibrium reaction

I was reading about the integrated rate law. However I have problems to follow the solution. I have an equilibrium reaction: [A]+[B]=[AB] with forward and back reaction. I approximate the ...
2
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1answer
51 views

Where does this equation for the activity in the gas phase equilibrium between N2, H2 and NH3 come from?

I have a question with Equilibrium Constant. I understand that for a reaction in equilibrium $aA +bB \rightleftharpoons cC +dD$ $$K_c= \frac{[C]^c[D]^d}{[A]^a[B]^b}$$ and $K_p$ is just using the ...
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41 views

Electrochemistry (Spontaneous Reactions)

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25 celsius? Pb2+(aq) + Cu(s) Ag+(aq) + Br-(aq) Li+(aq) + Cr(s) Fe3+(aq) + Cd(s) None of the Above. ...
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1answer
14 views

Cathode region in corrosion

The anode region is on the iron where the following reaction occurs: $$ Fe_{(s)}\rightarrow Fe^{2+}_{(aq)}+2\,e^- $$ and at the cathode region, the following reaction occurs $$ ...
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1answer
42 views

How does light get refracted through five lenses in a component of a spectrometer? [closed]

Question three in my Pre-lab questions for my Physical Chemistry practical is causing me problems. If a parallel beam of light hits the first lens with focal length 2F it will cause the light to ...
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4answers
4k views

Hypothetical: What happens to water as pressure increases to infinity?

I've asked a similar question here but the answer given shows the behaviour of water under general conditions. I'd like to know what the behaviour of water is like as pressures increase towards ...
1
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1answer
29 views

Rotational states of a molecule

How can you determine the possible rotational states of a molecule? Atkins Physical Chemistry book says that for linear molecules there are two possible rotational states, but what is the general ...
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1answer
29 views

Do liquid O2 and N2 form ideal solutions?

I suspect they do, but could not find data on this. (I mean at temperatures near those used in the distillation of liquid air.)
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1answer
51 views

Nuclear Spin Multiplicity of radicals

How do you calculate the nuclear spin multiplicity of radicals such as N2H+? How does the net charge on the molecular species effect its overall nuclear spin?
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1answer
37 views

Can there be more than one combination of reactant/product concentration for a specific equilibrium constant?

For an elementary reaction like $$\ce{A + B -> AB},$$ $$K_{c} = \frac{\ce{[AB]}}{\ce{[A][B]}}$$ and $$\frac{\mathrm{d}\ce{[AB]}}{\mathrm{d}t} = k\ce{[A][B]}.$$ If I let the reaction reach ...
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1answer
90 views

What is 'equality' of chemical bonds?

I was trying to solve a test series and I saw this question: "Why all $\ce{C-O}$ bonds in $\ce{CO_3^2-}$- are equal but not in $\ce{H2CO3}$?" I am completely confused by this question.
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1answer
47 views

Why is CO a major species only in fuel-rich combustion?

In fuel-rich combustion, my understanding is that enough fuel reacts and consumes all of the oxygen present. The combustion products $\ce{CO2}$ and $\ce{H2O}$ undergo dissociation until equilibrium is ...
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0answers
37 views

Femtosecond spectroscopy

Hi I am new to laser pump-probe spectroscopy and want to understand the concepts better. At the moment I am struggling to understand the following: When one takes absorption measurements with lasers ...
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1answer
48 views

How do I write the deterministic rate equation for bimolecular reaction with similar particles?

I was wondering how to write down the deterministic rate equation for a bimolecular reaction with similar particles. e.g. $$ \mathrm{A \overset{k_+}\rightarrow B +B}$$ and $$\mathrm{B +B ...
5
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1answer
63 views

Is There a Difference in the Definition of Complete and Stoichiometric Combustion?

My question has to do with some combustion related definitions. When the term complete combustion is used, is it assumed that the combustion is stoichiometric (reactants combine perfectly), but ...
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1answer
58 views

Calculating energy level from wavelength

The transition of an electron from a higher level to a lower level results in the emission of a photon of wavelength 350.0 nm. If the energy of the higher level is -3.24 x 10-19 J, calculate the ...
2
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0answers
31 views

How to efficiently reduce of ilmenite to pure titanium?

I am looking for a process in which reduces ilmenite to pure titanium with the highest yield possible. We are to use a process of our choice or one that we have created in conjunction with FactSage to ...
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0answers
35 views

How to determine an unknown gas in a tube with a massless piston at equilibrium conditions?

There is a massless piston that can move freely in a horizontal tube that is closed at both ends. To the left, there is a sample of helium gas at $300~\mathrm{K}$ and $4~\mathrm{atm}$. To the ...