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

4
votes
The permeability of a gas through rubber depends mainly on its diffusivity and solubility in rubber. $\ce{CO2}$ has a significantly higher solubility in rubber than $\ce{O2}$ and $\ce{N2}$, whereas t …
answered Jul 12 '16 by aventurin
1
vote
Your differential equations are correct. From $\frac{\mathrm{d}[\ce{B}]}{\mathrm{d}t} = -k_1[\ce{A}][\ce{B}]+k_2[\ce{A}] = 0$ follow the stationary solutions $[\ce{A}] = 0$ or $[\ce{B}] = \frac{k_2}{ …
answered Mar 30 '18 by aventurin
4
votes
The lifetime of the excited state is the reciprocal of the sum of rate constants which you are trying to find: $$\begin{align} \tau(T_1) = \frac{1}{\sum_i k_i(T_1)} &= \pu{6 \times 10^-3 s} \\ \sum_i …
answered Mar 8 '16 by aventurin
2
votes
There exist autocatalytic reactions than can show such a behaviour. E.g. a reaction $\ce{A + B \rightarrow 2\ B}$ might show the rate $k[\ce{A}] [\ce{B}]$. The reaction of permanganate with oxalic ac …
answered Mar 9 '16 by aventurin
4
votes
An isolated system consisting of liquid water and vapour is always in equilibrium. If you are applying heat to a system consisting of liquid water and vapour the system is not in equilibrium.
answered Feb 20 '16 by aventurin
3
votes
If a reaction takes place there should be a reasonable chemical equation. Calcium oxide and sulfur dioxide may react to give calcium sulfite: $$\ce{CaO + SO2 -> CaSO3}$$ On the other hand alkali met …
answered Feb 21 '16 by aventurin
8
votes
The question is flawed since we do not know whether the resulting mixture consists of a single phase or not (I guess that there are two phases). Moreover, the definition solute + solvent = soluti …
answered Dec 30 '16 by aventurin
2
votes
The most obvious approach for me would be to find a partition of the set of points into two subsets and two straight lines, one for each subset, such that the sum of the squared residuals over both pa …
answered Apr 29 '16 by aventurin
6
votes
$\ce{NaCl}$: Molar mass: $58.44~\mathrm{g~mol^{−1}}$ Melting point: $801\mathrm{°C}$ Specific heat capacity: $36.79~\mathrm{J~K^{-1}~mol^{−1}}$ Std enthalpy change of fusion: $27.95~\mathrm{kJ~mol^{ …
answered Jun 17 '16 by aventurin
2
votes
The Leidenfrost effect breaks down when stable film boiling stops and transition boiling starts. The temperature when this occurs is called the Leidenfrost point and its value is about $\pu{100°C}$ ab …
answered Sep 2 '18 by aventurin
4
votes
In nuclear decay we are normally interested in the behavior of atomic nuclei. Electrons from the atom's electron shell are considered to be spectators only and are ignored. Since the number of proto …
answered Sep 2 '17 by aventurin
3
votes
You might search the German Wikipedia using SPARQL via DBpedia. Go to http://de.dbpedia.org/sparql and run your query, e.g. PREFIX dbo:<http://dbpedia.org/ontology/> SELECT ?chem ?bp { ?chem a db …
answered Feb 22 '16 by aventurin
1
vote
From the given composition of the atmosphere you can calculate the mean molecular mass $M$ of air. Since Earth's gravitational field and temperature are assumed to be constant you can use the baromet …
answered Jan 14 '17 by aventurin
4
votes
"But we also know that, volumes of a gas diffused per unit time gives us rate of diffusion too. And in the question above, the volumes (in case they were given instead of moles) would have been dif …
answered Mar 20 '16 by aventurin