# Questions tagged [physical-chemistry]

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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### Electrode potential for metal-metal ion and metal-metal insoluble salt-salt ion electrode

So I read it in a book that The potential of metal-metal ion electrode and metal-metal insoluble salt-salt anion electrode is same while their standard potentials are not same. Standard potential ...
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### Boiling point of liquids [closed]

If we can have liquid - vapour equilibrium at any temperature what is the 'point' behind boiling point.Boiling point is just a special case of liquid - vapour equilibrium where partial pressure equals ...
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### Understanding “Gay-Lussac's law of Gaseous volumes/combining volumes”

Understanding "Gay-Lussac's law of Gaseous volumes/combining volumes". So I was reading Wikipedia and stumble across this. It defines it as follows "The ratio between the volumes of the reactant gases ...
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### Henry law and equilibrium

Is Henry's law a consequence of the equilibrium between a substance S in aqueous phase and the same substance S in gaseous phase? What I mean is, is it correct to treat Henry law as a manipulation of ...
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### Le Chatelier's Principle Having No Effect

Consider the following equilibrium system: $$\ce{2 IBr(g) <=> I2(g) + Br2(g)}$$ Would a decrease in the volume of the system effect the equilibrium? I think it would not affect the ...
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### Thermodynamics: ΔU = Q + W or U = Q?

Heat is the total kinetic energy of all atoms of the system. When work is done on the system it means that a part of system kinetic energy is used to do the work, and this work makes the surrounding ...
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### Find ratio of quantities of water and of argon in airtight container

I am working on my EJU exam past papers (2013) and got stuck at this question. Knowledge of high school or first year university chemistry is assumed. I honestly do not know where I should start. ...
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### Why does internal rotation of ethane give an energy spectrum asymptotically approaching a rotation based on $\nu=1$ rather than $\nu=0$?

I'm a physicist with very little knowledge of chemistry. Recently a chem colleague left a molecular model in my classroom, so I brought it back to her, and as I was walking down the hall with it, a ...
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### Gibbs free energy of activation and activation energy [duplicate]

What the difference between Gibbs free energy of activation and activation energy
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### Why is a LCAO necessary within Hartree Fock?

As I understand it, the electronic Schrödinger equation cannot be solved for polyelectronic systems. To circumvent this problem in the Hartree-Fock method, it is assumed that the polyelectronic ...
 \begin{align} \ce{CH4(g) + Cl(g) &-> CH3(g) + HCl(g)} &\quad ΔH^\circ &= \pu{-14 kJ mol-1}_\mathrm{rxn}\\ \ce{NH4(g) + Cl(g) &-> NH2(g) + HCl(g)} &\quad ΔH^\circ &= \...