Unanswered Questions
712 questions with no upvoted or accepted answers
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How much energy is required to operate a Sabatier reactor?
I am trying to model some industrial processes and having a hard time finding information about the Sabatier reaction. The Sabatier reaction combines $\ce{CO2}$ (and possibly $\ce{CO}$) with $\ce{H2}$ ...
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Is entropy maximum in equilibrium?
Usually, in the context of non-equilibrium thermodynamics, it is said that entropy achieves a maximum in equilibrium, so the Taylor series expansion of entropy around the equilibrium state as a ...
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Why does the heat of formation of organic radicals and positive ions decrease with their size and degree of branching at the radical or ionic site?
I am currently studying the textbook Mass Spectrometry, third edition, by Jürgen H. Gross. Chapter 2.4.3 Bond Dissociation Energies and Heats of Formation says the following:
The heat of formation ...
CommunityBot
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Curtin-Hammett principle to evaluate alkene insertion
Given an unsymmetrical alkene in a simple non-stereoselective catalytic hydrogenation reaction. If one would want to investigate the nuances in the catalytic cycle of a dihydride complex leading to ...
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Has a concept of temperature ever been defined in the context of a single atom?
I wonder if this answer to What would happen if we supercool and then superheat an atom very abruptly? goes far enough.
I almost wrote the comment:
I don't think we can even talk about the ...
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Whether the entropy change of the system is positive or negative
$$\ce{N2(g) + O2(g) ��� 2NO(g)}$$
My thinking: since gases are combined together, so there randomness or disorder gets decreased. Hence the sign of entropy change of the system should be negative.
...
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Calculating ΔH from bomb calorimetry
Suppose we carry out a reaction in a bomb calorimeter whose starting temperature is $298.15\ \mathrm K$. Here we assume $\Delta V$ is close enough to zero that we consider the process to be at ...
CommunityBot
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Extrapolating from a calorimetry lab to find a new delta T with different volumes and grams of substance
So, we just finished an AP chem lab where the question was basically:
Given the results of the lab were that $\pu{5 grams}$ of $\ce{CaCl2}$ and $\pu{45ml}$ of water produced a $\pu{13.33 ^\circ C}$ ...
CommunityBot
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If dG is a state function, why do reversible and irreversible paths differ?
For a reversible process at constant T,P in a closed system with no non-expansion work dG = 0. For an irreversible process under the same conditions, dG < 0. Since dG is a state function I would ...
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Can a droplet of formalin evaporate in midair while falling?
I am designing an evaporator for use in an enclosed environment. Due to the hazardous nature of formaldehyde, I want my evaporator to be wick-free.
The environment in which the evaporator will be used ...
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Can anyone explain this condensation pattern?
What is the hair-like polymer that condenses on the caps of the plastic cell vial? Inside vial are cells in a mixture of FBS and DMSO. The vials were frozen slowly in a special isopropanol-filled ...
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Theoretical temperature change in lime hydration
Calcium oxide (quicklime) and water have an exothermic reaction
$\ce{CaO + H2O \rightarrow Ca(OH)_2} \quad \quad \Delta H^{\circ}_f=-65.3 \; \mathrm{kJ \cdot mol^{-1}}$
Assume that I have 1 kg of ...
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690
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Theory of volume contraction in solution
When a solid is dissolved into a liquid, or two solids are amalgamated, their mutual volume will contract. For example, a crystal of sugar having a volume of one cubic inch dissolved into 10 cubic ...
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Glycine nucleation simulations
I am trying to run nucleation simulations of glycine in water. To generate a supersaturated solution, a solution that will crystallize, I need to know the solubility. Luckily for me, this data exists. ...
- 4,606
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Debye-Huckel theory with non-polar solvents
I want to calculate the activity coefficients of mixed solvent salt solutions. I am seeing very strange behavior when I try calculating the activity coefficient of salts in non-polar solvents using ...
- 1,690