All Questions
Tagged with aqueous-solution thermodynamics
37
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674
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Is the crystallization process of aqueous solutions of substances such as lithium chloride endothermic?
$\ce{LiCl}$ has an enthalpy of solution of $\pu{-37.1 kJ/mol}$, so its dissolution process is exothermic. Does this mean that it's crystallization process is exothermic? I'm asking since I've looked ...
- 261
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1
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In a reaction between Calcium Ammonium Nitrate or Urea with water, does Nitrogen Content and Purity affect how cold the solution gets?
Recently, I bought an ice pack that contained Calcium Ammonium Nitrate, and realized that it really didn't get cold. I came to the conclusion that perhaps Urea is more effective, yet it is still ...
1
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Predicting the vapor pressure of water ammonia solution
I am working on a project that involves the compressors for a vapor compression refrigeration cycle of R717 (ammonia) and came across something that has been boggling my mind a little bit for no good ...
1
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0
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65
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Volume change of solute addition to solvent
When making and manipulating high concentration stock solutions of sugar excipients, is there a way to predict the corresponding volume effect that occurs? I am asking in order to be able to create ...
- 19
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1
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391
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Sodium Silicide (NaSi) Synthesis, Reversability
I'm trying to understand a) the reaction that would produce $\ce{NaSi}$ from $\ce{Na}$ and $\ce{Si}$, as well as how to reverse the reaction of $\ce{NaSi}$ with $\ce{H2O}$. The product of the latter ...
- 61
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How do hydrogen bonds break the ionic bonds of a crystal lattice? [duplicate]
In the case of water dissolving sodium chloride. I was under the impression that hydrogen bonds were much weaker than the ionic bonds in sodium chloride, so how do they overcome the ionic bond ...
- 51
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224
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Osmotic pressure and Raoult's law co-relation?
Consider two compartments A and B joined. A contains pure water. B contains brine (dilute). Consider the Vant Hoff factor ($i$).
Obviously pressure over B is less than over A.
We also know that the ...
- 111
-3
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4
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How do I turn room temperature water into boiling water for drinking using an chemical/additive? [closed]
I am trying to create instant boiling water using a chemical of sorts, so that it can be consumed by a human. For example; someone could make tea without a kettle or any available water heating ...
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1
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2
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635
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Why do increasing concentrations of zinc chloride not linearly decrease the freezing point?
I did an experiment on how different concentrations of $\ce{ZnCl2}$ affect the freezing point of demi water. My results were that till a concentration of about $10\ \mathrm{mol\,dm^{-3}}$ the freezing ...
- 19
3
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Hydrogen Peroxide Heat of Dilution
Based on some data here, I am getting the heat of dilution of 100% $\ce{H2O2}$ as approx. 1100 cal/mole.
That's about 4.6 kJ/mol if I did my math right.
Is this a correct value? Seems too low to ...
- 1,638
6
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1
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How does increasing the ionic strength of an aqueous solution decrease the activity coefficient?
Activity is a new concept for me, and I am having a little bit of trouble understanding it.
For the equation:
$$\ce{aA + bB<=>cC + dD}$$
$$K_c= \frac{[\ce{A}]^a[\ce{B}]^b}{[\ce{C}]^c[\ce{D}]^...
- 345
2
votes
1
answer
2k
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Why is lithium bromide used in absorption refrigerators?
Lithium bromide refrigerator
Why is lithium bromide used in absorption refrigerators? It is more expensive than sodium chloride. The wikipedia article on lithium bromide says it is extremely ...
- 3,848
1
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1
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24k
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Is the dissolution of sodium acetate trihydate endothermic?
Sodium acetate trihydrate dissolves in water to its constituent ions:
$$\ce{NaOAc.3H2O (s) ->[H2O] Na+ (aq) + OAc- (aq) + 3H2O (l)}$$
The crystallisation of sodium acetate from a supersaturated ...
- 121
2
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2
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Which formula is correct for calculating the heat of dissolution?
I want to calculate the energy change when a solute is dissolved in water. I know that I can achieve this by using the equation $q=mc \Delta T$. My question is does the mass ($m$) change with the ...
- 113
1
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1
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Can we determine apriori the volume of solvent in an electrolyte
Suppose I would like to create a one molar solution of NaCl in water. The molar concentration is defined as
$c_i=\frac{n_i}{V} $
$n_i=1$ in this case. I need to take 58.5 grams of NaCl (atomic ...
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