All Questions
35
questions
2
votes
0
answers
58
views
Phase diagram of ammonium hydrosulfide, a volatile salt
Salts (ionic compounds) usually have low volatility due to the strong ionic bond.
However, there are exceptions. Smelling salts decompose and release ammonia gas.
What is "volatile"?
If a ...
- 972
-2
votes
1
answer
125
views
Can phosphorous penta hydroxide [P(OH)5] exist? [closed]
I was looking at the oxyacids of Phosphorous and it is given that (in Wikipedia article of "Phosphorous acid"), some of these acids (Eg: $H_3PO_2$ and $H_3PO_3$) exist in a dynamic ...
- 55
1
vote
0
answers
42
views
Why is it that in a buffer solution the equilibrium concentrations may be assumed to be the initial concentrations? [duplicate]
Considering the Henderson–Hasselbalch equation,
$$\text{pH} = \text{p}K_a + \lg \frac{[\ce{AcO⁻}]} {[\ce{AcOH}]}$$
$$\text{p}K_a = \lg \frac{[\ce{AcO⁻}][\ce{H⁺}]} {[\ce{AcOH}]}$$
Why are the values ...
- 11
1
vote
1
answer
107
views
What are the dissociation constants of hydronium and hydroxide ions? [duplicate]
Context
The answer to How to calculate Ka for hydronium and Kb for hydroxide?, water was regarded as solvent once and base (or equivalently acid) once while citing Reference 1 (1986) and made no ...
- 2,304
0
votes
1
answer
151
views
Problem understanding the rate of reaction of reversible reactions
Case 1:
$$\ce{CH_3COOH + NaOH<=>CH_3COONa + H_2O}$$
At equilibrium, there remain extremely small concentrations of the reactants (acetic acid and sodium hydroxide), and comparatively large ...
- 23
1
vote
2
answers
338
views
Effect of H+ concentration on equilibria
Considering the two equilibriums below, when the $[\ce{H+}]$ decreases, my book says that equilibrium \eqref{rxn:2} will shift to the left by a greater extent compared to equilibrium \eqref{rxn:1} ...
- 242
-3
votes
1
answer
537
views
How to calculate Kp without knowing the volume? [closed]
I have the following chemical equation:
$$\ce{Sb2S3 + 3H2 <=> 2 Sb + 3H2S}$$
I have $\pu{1000 grams}$ of $\ce{Sb2S3}$ that reacts with $\pu{10 grams}$ of $\ce{H2}$ in a reactor at $\pu{713 K}$.
...
-1
votes
1
answer
161
views
Finding a Mistake Calculating the pH of Ammonium Acetate
I'm trying to calculate the $\mathrm{pH}$ of a $\pu{0.10 M}$ solution of ammonium acetate, and I am struggling to find what mistake I am making within the following calculations:
We know that $\dfrac{[...
- 102
-1
votes
2
answers
255
views
Why does this acid-base reaction occur?
My teacher told me about the reaction of sodium peroxide with water:
$$\text{Na}_2\text{O}_2 + 2\text{H}_2\text{O} \ce{->} \text{H}_2\text{O}_2 + 2\text{NaOH}$$
Now, the concentration of products ...
- 750
-2
votes
1
answer
1k
views
Preparation of a HCN/NaCN buffer that has a pH of 9.8 and an osmotic pressure of 1.35 atm at 298 K
You are asked to prepare $\pu{2.0 L}$ of a $\ce{HCN/NaCN}$ buffer that has a $\mathrm{pH}$ of $9.8$ and an osmotic pressure of $\pu{1.35 atm}$ at $\pu{298 K}$. What masses of $\ce{HCN}$ and $\ce{NaCN}$...
- 19
0
votes
1
answer
2k
views
Reaction of hydrogen peroxide with sodium carbonate [closed]
In my book the following acid base reaction is written:
$$\ce{H2O2 + Na2CO3 -> Na2O2 + H2O + CO2}$$
But I found that the $\mathrm{p}K_\mathrm{a}$ value of $\ce{H2CO3}$ is less than the one for $\...
- 17
2
votes
1
answer
469
views
Ligand substitution reaction in coordination compounds
I know that the following substitution reaction can take place:
$$\ce{[Cu(H2O)4]^2+ (aq) + 4NH3 (aq) -> [Cu(NH3)4]^2+ (aq) + 4H2O (l)}$$
This is because ammonia is a stronger ligand than water.
...
- 1,280
1
vote
0
answers
108
views
Finding ionic radii from solubility data and density
$\pu{5.35 g}$ of a salt $\ce{ACl}$ is dissolved in $\pu{250 ml}$ of solution. The $\mathrm{pH}$ of the resultant solution was found to be $4.85.$ Find the ionic radius of $\ce{A+}$ and $\ce{Cl-}$ if ...
4
votes
3
answers
2k
views
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 ...
2
votes
0
answers
269
views
Amount of benzoic acid required to alter pH of a NaOH-solution
I am trying to do a practice problem but I can't figure it out:
How many grams of benzoic acid needs to be added to 0.10 l of a NaOH-solution with a concentration of 1.0 mM to reduce the pH of said ...
- 51