All Questions
Tagged with free-energy acid-base
6
questions
1
vote
0
answers
83
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Why doesn't acid dissociation always have K>1?
Acid dissociation is usually exothermic, and it has an increase in entropy, so the change in Gibbs free energy should be negative. So why isn't always $K_\mathrm{a}>1$ in accordance with $\Delta G^...
- 206
3
votes
0
answers
111
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Gibbs free energy of mixing in a control volume
I'm trying to model the amount of energy lost due to mixing of a $\mathrm{HCl}$ solution using the Gibbs free energy of mixing. However, I really like a second opinion on the model and the results, ...
- 131
4
votes
3
answers
2k
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If change in free energy (G) is positive, how do those reactions still occur?
I was doing a couple of problems for homework:
Calculate $K_\mathrm{sp}$ of $\ce{AgI}$ at $55.0\ \mathrm{^\circ C}$
Calculate $K_\mathrm{b}$ of $\ce{NH3}$ at $36.0\ \mathrm{^\circ C}$
I have to use ...
3
votes
2
answers
20k
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How to calculate Gibbs free energy from pKa?
Is it possible to calculate Gibbs free energy ($ΔG = -RT\ln K_\mathrm{eq}$) of an acid dissociation reaction using the $\mathrm{p}K_\mathrm{a}$? If so, how?
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5
votes
2
answers
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What is the source of discrepancy in the calculation of Standard State Gibbs Free Energy change of the reaction of HCl (l) dissolving in water?
I have calculated $\Delta_\text{r} G^o$ two different ways and got completely different results. Why? What assumptions have I made incorrectly, particularly in the first calculation shown below?
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- 547
6
votes
1
answer
3k
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Pourbaix diagram – writing reactions
How would you go about writing the reaction between water and chromium metal under standard acid and base conditions?
I know you would have to look at the vertical lines at pH 0 and 14 but I don’t ...
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