Andy
  • Member for 6 years, 10 months
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What is the difference between ΔG and ΔG "with an o on top"?
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7 votes

A simple explanation would be that the "o on top" denotes standard state and the one without the "o on top" denotes conditions that are not standard state. However, that may not allow you to "get it" ...

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What exactly does the term "gram atoms" mean?
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6 votes

$\ce{MgB2}$ is 1 gram-molecule of $\ce{MgB2}$ but 3 gram-atoms of $\ce{MgB2}$. Why is this so? Let us consider this problem in the familiar mole: If we were asked how many moles of the substance (...

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Hydration number: Carbonic acid in water
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5 votes

You may wish to refer to the publication of Saykally et al., The hydration structure of aqueous carbonic acid from X-ray absorption spectroscopy Basically, to determine hydration number, X-ray ...

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Understanding a passage related to salt buffer
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5 votes

There is no such thing as $\ce{NH4OH}$ . They would react to form water and ammonia. Thus, to say that both exist in the solution at such high concentrations would be mistaken. They would react. ...

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Why is an alcohol proton so shielded?
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4 votes

Oh, I was just reading about this. This excerpt points out the factor contributing to the chemical shift observed in alcohols The extent of hydrogen bonding varies with concentration, temperature, ...

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Boiling/melting points of cyclohexane and cycloheptane
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4 votes

There are not many reputable sources on the matter (as I could find) since it seems that cycloheptane isn't the most popular chemical around (poor guy) but I will present you with the best explanation/...

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Why water vapors exerts pressure rather than diffusing in air before reaching the boiling point of water?
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3 votes

I be mistaken, but are you referring to vapor pressure? Vapor pressure or equilibrium vapour pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed ...

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How to determine whether the enthalpy of solution is positive or negative by calorimetry?
3 votes

The sample takes in the heat from the water, so it takes in energy to "form" the solution and the water thereby loses it, becoming a lower temperature. You need to realize the reference point is not ...

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When is phosphorus a polyatomic molecule?
2 votes

Phosphorus is most common as white phosphorus (but more stable as red phosphorus) and in this form, it exists as a tetrahedron, or $\ce{P4}$. Chlorine is most stable as a diatomic molecule, as you may ...

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Why so differance in alkali halide's crystal forms?
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2 votes

Perhaps you have heard of the following terminology: "rock salt", "cesium chloride", "zinc blende" structures? If so, you may recall that in this case, the main factor dictating structure is "size" or ...

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MO for $N_2^{2-}$
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2 votes

This an image of the molecular orbital of $\ce{N2}$. If we add 2 more electrons, they will enter singly into the 2 antibonding pi orbitals and since bond strength is defined as bonding electrons minus ...

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Given a forward reaction with positive enthalpy, is its reverse reaction be endothermic or exothermic?
2 votes

Yes, in a reverse reaction the sign changes. That is because Enthalpy is a state function, one that depends on only the current state of the function. That means the energy required to push a reaction ...

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Is p-bromophenol more acidic than p-chlorophenol?
2 votes

Disclaimer: This is not necessarily the "correct" answer as many factors play roles and it would be difficult to describe the observation so simply. I'm not sure I can provide an easily "correct" ...

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Solubility determination of Ca(OH)₂ in water
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2 votes

The self ionization of $\ce{OH}$ is $10^{-7}$. If the concentration of $\ce{Ca(OH)2}$ is greater by a few magnitudes, then the self ionization should not matter much. In fact, $\ce{Ca(OH)2}$ is ...

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I need to find the Ka of a weak acid in titration with a strong base
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1 votes

I’m not sure if I’m missing your question, but I thought that perhaps you could use the relation $\mathrm{pH}=\mathrm{p}K_\text{a}$ at the half equivalence point? The answer would be still incorrect ...

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Molar heat of fusion of ice?
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1 votes

Your interpretation is correct. The molar heat of fusion is the amount of heat necessary to melt a mole of ice at its melting (or freezing) point. That means, to get 1 mole of water from 1 mole of ...

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Titrating and the addition of acidic distilled water
1 votes

Unfortunately I could not find any sources that specifically address your question so I will be answering using logic. If you notice any fallacies or points you disagree with, please point them out. $...

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Why might the O—H stretch in the IR of MY triphenylmethanol product be less intense than expected?
1 votes

A possible explanation would be the concentration of sample you used. Of course, if you are confident that you had utilized sufficient concentration then there may be another reason for the decreased ...

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Coloration of substances because of F-Centers
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1 votes

For a simple explanation, we could explain the coloration of the substance by the absorption of the energy of the electrons in the void, which leads to the color of the compliment color (as is ...

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After mixing, which species has the dominant affect on the pH of the solution that remains?
0 votes

You need to provide the concentration of acetic acid. However, if I were to guess, I would say that the hydrochloric acid completely reacts with the cesium hydroxide, and the remaining cesium ...

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Why does rock salt change colour when it's heated
0 votes

I'm not too sure what you are asking. If you are refering to rock salt as in sodium chloride (NaCl), I too am at a loss at how you would have created such an effect. I will assume that you have ...

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How does one determine the relative basicity of a nitrogen in a molecule?
0 votes

For amine basicity: Basicity decreases with increasing s character Basicity decreases with increasing stability, due to resonance/ delocalization https://www2.chemistry.msu.edu/faculty/reusch/...

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pKaH of pyridine versus other imines
-1 votes

One interpretation of acidity is the ability to stabilize a negative charge (since the electron is generally kept by the acid, and the proton harbors the positive charge, if we go by bronsted lowry) ...

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Effect of dilution on pH for HCl
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-2 votes

Yes, you will definitely need to account for common ion effect. However, use Kw to compute the pH. Assume that there is a complete dissociation by $\ce{HCl}$. However, you would need to solve the ...

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