Questions tagged [solutions]
This tag should be applied to questions dealing with solutions of any kind. A solution is a liquid or solid phase containing more than one substance where, for convenience, one (or more) substance(s) called the solvent is treated differently from the other substances, which are called solutes. If water is the solvent, then the more appropriate 'aqueous-solution' tag should (also) be specified.
1,029
questions
-2
votes
2
answers
51
views
Explanation for Raoults Law
The vapour pressure of pure liquids is independent of quantity of substance.
But when in a solution, the vapour pressure of the components are given by
$$P_A=P^°_AX_A$$$$P_B=P^°_BX_B$$
Since $A-A$, $A-...
- 1
4
votes
1
answer
1k
views
Why is glass a mixture and not a solution?
While studying mixtures and solutions, I read that glass is a mixture and not a solution.
Then I searched over the Internet about it, but I got the same answer that it is a homogenous mixture.
But ...
- 183
1
vote
0
answers
29
views
Magnetic surface removal
I have a DIY project made from used hard disk. Certain HDD models contain precision glass disks plated with magnetic surface, usually done with magnetron sputtering. I am searching for a substance I ...
- 111
3
votes
1
answer
342
views
Enthalpy change of a solution of 1-pentanol in 1-butanol
I came across a question asking to indicate the enthalpy of solution for a solution of 1-pentanol in 1-butanol.
The options were the following:
$\Delta H < 0$
$\Delta H \approx 0$
$\Delta H >...
- 173
1
vote
0
answers
41
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
0
answers
61
views
Why does the melting point of hexafluorosilicic acid differ that much in these two solution concentrations?
From the Wikipedia article for hexafluorosilicic acid:
Melting point:
ca. 19 °C (66 °F; 292 K) (60–70% solution)
$<$ −30 °C (−22 °F; 243 K) (35% solution)
What's the reason for this huge ...
user85778
0
votes
1
answer
67
views
Why do laundry detergents go bad?
Common lore on the internet is that liquid laundry detergents go bad 1-2 years after they are purchased. Is this true? I'd like to understand the chemistry behind this. This is the laundry detergent I ...
-2
votes
1
answer
62
views
How can a volatile solvent make an ideal solution with a non-volatile solid solute?
I ask because to make an ideal solution the intermolecular forces between the molecules of solvent and solute respectively should be similar and after mixing they should also be similar to what they ...
2
votes
1
answer
84
views
Are all salts completely dissociated in solution when put in smaller amounts than their molar solubility?
From what I understand, the solubility is given in terms of molar solubility (or $\pu{K_{sp}}$), from which it can be easily calculated). Indeed, the saturation point represents the maximum amount of ...
- 67
1
vote
2
answers
539
views
How to prepare solution of liquid reagent of the given molar concentration?
I have a liquid reagent with molecular mass $M = \pu{294.08 g mol^-1}.$ I'd like to prepare $V = \pu{400 ml}$ of solution of that reagent with a concentration $c = \pu{100 mM}.$
Does it mean I have to ...
- 135
-3
votes
1
answer
104
views
Can acids contain OH-? [closed]
Given that a solution contains $\ce{OH-}$ ions can we sufficiently determine the substance is a base? From my understanding, an acid may still contain $\ce{OH-}$ ions. However, the concentration of $\...
2
votes
0
answers
74
views
How do I plot ternary phase diagrams using Flory-Huggins solution theory?
I have three components, $A,B,C$, with 3 exchange parameters: $\chi _{AB}, \chi _{BC}, \chi _{AC}$. I want to create a FH ternary diagram to see how such a mixture behaves and how phase separation ...
- 121
-3
votes
2
answers
112
views
Powder left everywhere after solution was left to evaporate. What could it be?
I dissolved a coin made of silver and copper and probably other metals in nitric acid. I neutralized the solution with some sodium hydroxide and then added salt(NaCl) to make Silver Chloride. A white ...
-2
votes
3
answers
817
views
Why do we have to prevent the hydrolysis of iron(III) nitrate?
I want to make particular concentration of ferric ions from $\ce{Fe(NO3)3.9H2O}$, and then I found this video
It says that we have to add nitric acid to prevent iron from hydrolysis, what does it mean?...
0
votes
1
answer
131
views
Why causes the curvature of the line in pressure-composition graph?
I have been studying about liquid solutions and came across these graphs.
From the first graph it is evident that the solution considered has been assumed ideal as there is no deviation from ideal ...
