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.

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19 votes
2 answers
13k views

What causes the lowering of vapour pressure in volatile/nonvolatile solvent mixtures?

"Based on Figure 13.18, you might think that the reason volatile solvent molecules in a solution are less likely to escape to the gas phase, compared to the pure solvent, is that the solute molecules ...
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9 votes
1 answer
19k views

Why do some substances ionize instead of dissolving in water?

My question can also be understood as what make something electrolyte or nonelectrolyte? I think this question stems mainly from my confusion with the definitions of ionizing and dissolving. ...
3 votes
1 answer
449 views

Why do acids usually completely react with bases?

When a neutralisation reaction happens, for example, $ \pu{100 mol l^-1}$ of $\ce{HCl}$ with $\pu{100 mol l^-1}$ $\ce{NH_3}$, why does all of the base and acid get converted to salt? Why isn't there ...
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4 votes
1 answer
119 views

Can fully-hydrogenated oils be mixed with unsaturated oils for use in food (margarines, etc)?

Would it be feasible to mix fully hydrogenated oils with unsaturated oils (eg. soybean oil) to create an edible fat with the consistency of margarine? If so, what is the motivation for ...
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11 votes
1 answer
61k views

Does concentration of salt increase or decrease rate of rusting?

I want to know whether increasing the concentration of salt, specifically $\ce{NaCl}$, increases or decreases the rate of rusting. There are conflicting theories that explain opposite outcomes: ...
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28 votes
5 answers
17k views

Why is water "the universal" solvent?

This is an old question that our textbook tried to answer but worsened the situation. Many things are soluble in water. So many, that studying solutions will always require studying aqueous ones. It ...
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5 votes
1 answer
2k views

Why do some solid chemicals dissolve better in colder water?

I just discovered that some solid chemicals, such as $\ce{Na2SO4}$, dissolve better in cold water than hot water from here and would like to know if there is any particular reason as to why. Is it ...
9 votes
3 answers
1k views

Where does the Fe(III) ion go?

Iron(II) sulphate solution is added to a test-tube. Following this, potassium manganate solution is added gradually to the test-tube as well. The observation seen is that the green solution turns pink ...
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1 vote
1 answer
293 views

how protons(H+) react with matter and cause the solution to be acid?

For example if my hands were put in a HCl solution how does the protons in the solution which in high amounts will interfere/react with my hand(skin->proteins..) and cause it to burn...or how protons ...
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2 votes
0 answers
294 views

How to derive the energy of solvation equation?

The work done as a ion is solvated is given by: $-z^2e^2/8\pi\epsilon r$ but since the top line can be written $Q^2$, for simplicity I will say the equation is $-Q^2/8\pi\epsilon r$. Is this derived ...
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3 votes
1 answer
116 views

Why is the maximal percent concentration of acids similar to their molar mass

Why is the usual percent concentration of a concentrated acid's solution similar to its molar mass? For example: ...
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0 votes
1 answer
558 views

Aqueous Chemistry: Ranking Ion Concentration

I am trying to rank the concentration of $\ce{PO4^3-}$, $\ce{NO3^-}$, and $\ce{Na+}$ that remain in a reaction. The reaction occurs when 100mL of 1.0M $\ce{Na3PO4}$ solution is mixed with 100mL of 1....
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2 votes
2 answers
462 views

How to determine the composition for a sucrose/ zinc nitrate solution from its freezing point?

A $4~\mathrm{g}$ mixture of sucrose ($\ce{C12H22O11}$) and zinc nitrate ($\ce{Zn(NO3)2}$) is dissolved in $150~\mathrm{g}$ of water. If the resulting solution freezes at $-0.768~^\circ\mathrm{C}$, ...
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2 votes
1 answer
3k views

Applying the Solubility Guidelines is AgClO4 soluble or insoluble?

The book I am using is "General Chemistry: Principles and Modern Applications by Ralph H. Petrucci. On page 158 the Solubility Guidelines for Common Ionic Solids is given. Rule 3 states that, "Salts ...
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1 vote
2 answers
2k views

What chemical substance is obtained by dissolving C60 in olive oil?

What chemical substance/component would be obtained of dissolving $\ce{C60}$ in olive oil? Would buckminsterfullerene (bucky-ball) change its spherical fullerene structure (soccer ball-like) into ...
  • 217
3 votes
1 answer
5k views

What chemical will dissolve the plastic coating on circuit boards

I'm trying to reclaim the metals on circuit boards and the vast majority is underneath the plastic coating. It is a brittle plastic that chips off in small flakes when etched but that process will ...
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2 votes
1 answer
5k views

In water, will sucrose be hydrolysed by water to form glucose and fructose molecules? [duplicate]

If I dissolve sucrose sugar ($\ce{C_12H_22O_11}$) in water, would the water readily hydrolyse the sucrose sugar to form glucose and fructose sugars?
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1 vote
0 answers
189 views

Kinetics of the conversion from metal oxide to metal hydroxide in water

How long can a metal oxide such as magnesium oxide remain in solution before being converted to the metal hydroxide?
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4 votes
1 answer
2k views

Can Ice Packs Freeze Water at 21 °C?

I receive $120~\mathrm{mL}$ bags of medicine in sterile water. The medicine is refrigerated and then packed with a significant amount of ice packs in an insulated bag. Generally three times the volume ...
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5 votes
1 answer
962 views

HCl/diethyl ether + Nitrogen?

Just wondering if anyone can tell me why bubbling nitrogen through a solution of $\ce{HCl}$/diethyl ether catalyst would remove said mix from my solution. My current thought is that the $\ce{N2}$ ...
  • 1,973
14 votes
6 answers
31k views

When I dissolve sugar in my cup of tea/coffee, does it become a liquid?

When I dissolve sugar in my cup of tea/coffee, does the sugar go from being a solid to being a liquid? Related: https://physics.stackexchange.com/questions/5562/what-keeps-the-sugar-suspended-in-the-...
0 votes
2 answers
2k views

Which of the following elements forms a water-soluble, alkaline oxide?

An element burns in oxygen to form a solid oxide which dissolves in water. The pH of the resulting solution is greater than seven. Which one of the following could the element be? A. sulphur B. ...
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1 vote
1 answer
69 views

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 ...
3 votes
3 answers
3k views

What is the procedure to create stock solutions?

Until now to execute this recipe, each time i had to count those milligrams/Liter. An enough difficult procedure. I am posting here this question to help me understand the procedure of creating ...
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0 votes
1 answer
4k views

Why is the water column empty in ICE table

In the ICE table pure solids and liquids have a value of one in the equilibrium expression but when we create an ICE table, why is the $\ce{H_{2}O}$ column empty? Should it not have a value of one?
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0 votes
1 answer
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Volatile and non-volatile solutes in solution

What is the difference between having a volatile versus a non-volatile solute at the boiling point of the solution? I have been getting mixed answers online concerning the differences outlined above. ...
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4 votes
2 answers
773 views

Mixing of powders to make stock solutions

For a solution such as: Luria-Bertani (LB) Broth: 10 g tryptone 5 g yeast extract 10 g of NaCl ($M = 58.44\ \mathrm{g/mol}$) q.s. to 1 l, pH to 7.2, autoclave. I would like to make a bulk amount ...
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1 vote
2 answers
723 views

Solution, hardener and metal required to cast key duplicates

I just watched this YouTube video for a DIY key duplication system and was trying to figure out what all the material components could be: The "mold solution" (parts 1 and 2) The "hardener" The "low ...
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1 vote
1 answer
241 views

Home-made way to detect lye in solution

I believe that electrolysis of salt water creates lye ($\ce{NaOH}$ - sodium hydroxide). In salt water, there's $\ce{Na+}$, $\ce{Cl-}$, $\ce{H+}$ and $\ce{OH-}$ as of ionts. So at cathode, you get $\...
9 votes
2 answers
30k views

How much does water expand when heated, and does salt affect that?

For this question, assume all things not mentioned are perfectly controlled, all at 14.7lbs of atmospheric pressure, and water is 100% pure of anything not mentioned, with no dissolved air. Given a ...
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1 vote
1 answer
565 views

How does the Freezing Point fall in a solution?

It is known that addition of a non-volatile solute to a volatile solvent(liquid) to give a solution reduces the Vapour Pressure of the solution (well solvent actually as only solvent is volatile). ...
6 votes
1 answer
599 views

Can a solid and liquid be miscible?

To be specific, what I mean is: is the following situation possible? At given temperature T, there are two substances, X and Y, such that pure X is a solid, pure Y is a liquid, and X and Y mix to form ...
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3 votes
1 answer
130 views

Residual stress in polymer coatings

A paper talks about the residual stress when coating polymers. It says that residual stress is the sum of the "heat stress" (due to the difference in thermal expansion coefficients) and the "shrinkage ...
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5 votes
2 answers
12k views

What properties does a solvent with a high dielectric constant have?

My professor commented that water has a higher dielectric constant than alcohol. Okay, but on what basis? He didn't elaborate; he asked us which one seemed "more electric" and most answered water. ...
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5 votes
2 answers
4k views

why do we obtain a sigmoid curve in vapour pressure versus temperature graph

i have recently got a question in an assignment, which was somewhat like this what would be the shape of curve obtained in a graph between vapour pressure & temperature of a binary solution in ...
5 votes
1 answer
2k views

Byproducts of the neutralisation of hydrochloric acid with sodium hydroxide

Given a 1 M concentration of $\ce{HCl}$ and $\ce{NaOH}$ here are the pHs: pH of $\ce{HCl}$: 1 pH of $\ce{NaOH}$: 13–14 and of course water has a pH of 7. Here is a reaction that is most likely to ...
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3 votes
1 answer
841 views

Electric field effect on reactions

What would be the effect of putting a solution in a strong electric field? Would the reactions in the solution be affected? I'm thinking yes – lots (if not all) – chemistry is dependent on charge (...
  • 18k
2 votes
1 answer
1k views

High/low density water solution values

I would like to know what min and max values of densities are achievable with water solutions. There are some conditions: 1. Normal or close to normal temperature; 2. Non-radioactive solutions/...
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3 votes
1 answer
44k views

Calculating the molar mass of a solute from freezing point

A $\pu{4.305 g}$ sample of a nonelectrolyte is dissolved in $\pu{105 g}$ of water. The solution freezes at $\pu{-1.23^\circ C}$. Calculate the molar mass of the solute. $k_f$ for water is $\pu{1.86 C/...
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6 votes
1 answer
506 views

When are we justified in making assumptions in questions

The density at $20^\circ\mathrm{C}$ of a $\pu{0.500 M}$ solution of acetic acid in water is $\pu{1.0042 g/mL}$. What is the molality of the solution? The molar mass of acetic acid is $M(\ce{CH3CO2H})=\...
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3 votes
2 answers
18k views

Why do ionic substances with higher lattice energies tend to be less soluble in water than substances with lower lattice energies?

I understand that that energy is required to overcome intermolecular forces holding solute particles together in the crystal, but I don't understand how this relates to lattice energies and respective ...
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1 vote
1 answer
90 views

Entropies of Solvation for Chlorate and Nitrate Anions

Can anyone find any data on the entropies of solvation for these two anions in water solution? I can't find any.
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2 votes
2 answers
175 views

How do I find a concentration from a sample tested on a spectrophotometer?

I have an assignment to calculate the concentration from a sample. The assignment is: You have 100 µL of RNA. You take 10 µL from the sample and put it in 990 µL of water in the cuvette. The OD is 0....
1 vote
2 answers
208 views

Finding the molarity of the combination of two solution reacting with each other

I have a question that gives two concentrations and asks for the mass of $\ce{HCl}$ formed by the reaction. $$\ce{H2SO4 + NaCl ->Na2SO4 + HCl}$$ I have two concentrations: $\pu{250 mL}$ of $\pu{4....
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1 vote
1 answer
2k views

Making a solution with two solutes

I need to make a solution that has a 15% (wt/wt%) HCl acid concentration and a 6% (wt/wt%) NaI concentration. I'm not sure yet how much of this solution I will be required to make so a general recipie ...
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4 votes
0 answers
106 views

Synthesizing monodisperse PbS quantum dots

For a research project, I am trying to synthesize lead (II) sulfide quantum dots using the method of Li et al.. I am injecting sulfur dissolved in 1-octadecene into a mixture of $\ce{PbO}$, oleic ...
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4 votes
3 answers
2k views

Why are solutions electrically neutral?

I keep reading that solutions are electrically neutral, but I've never read an explanation. I've read after the fact justifications, such as one problem which asked me to calculate the force of ...
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1 vote
2 answers
205 views

How can water with a very low hardness have substantial buffer capacity?

My freshwater fish tank has a pH of 5.8 and a KH value in excess of 40 or 720+ppm while still maintaining a water hardness of 20 ppm or GH< 1 now I am a math/phsyics student but I have taken both ...
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5 votes
2 answers
409 views

What solvent would have the fewest ions?

We know that water auto-ionizes (to a rather small extent). My question is which solvent would have the fewest ions (or at least fewer ions than water). I'm thinking that perhaps some kind of ...
  • 18k
1 vote
3 answers
9k views

Why is a buffer solution most effective when concentrations of salt and acid are the same?

Why does a buffer work most effectively when the concentration of salt and acid is 1:1?
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