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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3answers
112 views

How are compounds within a complicated mixture detected?

I was reading an article about an independent pharmaceutical watchdog group called Valisure which recently released a report stating that they found Benzene, a toxic substance, in many bottles of ...
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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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120 views

How to crystallize a solution of N,N-dimethylphenylalaninemethylesterhydrochloride without heating it?

I have an aqueous solution of N,N-dimethylphenylalaninemethylesterhydrochloride and I need to crystallise it as a salt. I'm afraid of increasing the temperature or the concentration of acid due to the ...
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1answer
180 views

Do azeotropic mixtures evaporate proportionally?

Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point? Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
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2answers
488 views

Why are entries missing on a solubility data chart for ionic compounds? [closed]

There is a solubility chart in my college chemistry class text for "Solubility of Ionic compounds in water". I have copied and pasted image of chart below. I was surprised to find a dozen ...
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1answer
40k 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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2answers
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Given the volumes: determine the pH and the final temperature of a mixture knowing only the initial pH and the temperature of the un-mixed components

I have a pretty basic question but the last time I took Chemistry was in 2007. I am studying the Navy's Nuclear study guide for their interviews and one of the question I am faced with is below. ...
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1answer
105 views

Finding pH using the -log, why does my calculation differ from the book's answer?

An aqueous solution containing 0.0020 mol/L barium hydroxide, what is the pH? I do the following: 14-(-log(0.0020))=11.3pH. The answer is 11.6. 2.0*10^-3 mol/L sodium hydroxide solution, what is the ...
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1answer
2k views

Mass of sugar that was added to the water (Raoult's law)

Water has a vapour pressure of $15.5~\mathrm{mmHg}$ at $25~\mathrm{^\circ C}$. An unknown amount of the non-volatile sugar glucose ($\ce{C6H12O6}$) is added to $1.31~\mathrm{kg}$ of water and the ...
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1answer
376 views

How do I utilize Henry's Law Constant?

I have tried for several hours to answer this question with no luck. I believe I may be missing a couple of steps or I am not utilizing the given information properly. Nonetheless, some guidance will ...
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3answers
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Effect of pressure on solubility of salts

The volume of certain saturated solution is greater than the sum of the volumes of the water and salt from which it is made. On increasing pressure solubility of this salt (a) Increases (b) Decreases (...
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1answer
563 views

Making a 10L HCl solution with 8.77% HCl in a 100 mL solution from a 16 M stock solution

How would you make 10L of HCl solution with 8.77% HCl in 100 mL from a 16M stock solution. Here's what I have tried so far: I put my percent HCl and got that down to match with the moles of HCl I ...
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1answer
739 views

Are my protolysis equations right?

We had the task to solve several salts in water and measure the pH value of the solution. After that we should "create" the protolysis equation and to tell about Chemical equilibrium[s]. I get some ...
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1answer
7k views

p-value for ions in a solution?

The question in my class notes read as: Calculate the p-value for each ion in a solution that is $2.00 \times 10^{-7}\ \mathrm{M}$ in $\ce{NaCl}$ and $5.4 \times 10^{-4}\ \mathrm{M}$ in $\ce{HCl}$....
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1answer
4k views

Highest osmotic pressure

I’d like to ask a question and clear my misunderstanding. Which of the following 0.01 M solutions have the highest osmotic pressure? -$\ce{NaCl}$ -$\ce{C12H22O11}$ -$\ce{BaCl2}$ -$\ce{CO(...
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2answers
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will splitting a solution will keep the concentration values (and moles) the same? [closed]

I have this exercise from my H.W: and I am asked: if we split the solution into 3 different containers equally - how many moles will the solution have in each container? will the Cl- concentration ...
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2answers
17k views

What is an equivalent?

I want to know what is an equivalent and how is it different from equivalent mass. How to calculate and why is it used in chemistry for knowing concentration?
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3answers
168 views

Finding equilibrium concentrations in solution from initial reagent concentrations and equilibrium constant

We have the following reaction: $$\ce{A + B<=>2C +D}$$ The initial concentration of $\ce{A}$ and $\ce{B}$ are $\pu{1M}$ each. $K_c$ is $\pu{1.0E8}$. Find the equilibrium concentration of $\ce{A}$...
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1answer
53 views

How many boiling points does a mixture of liquids have?

Let's say I have a mixture of two miscible liquids. I want to get the liquids by fractional/pure distillation. My textbook says a mixture boils over a range of temperatures. On the contrary, another ...
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1answer
50 views

Salt solubility and solvent dissociation

A textbook, describing a qualitative test for the $\ce{Al^3+}$ cation in which you use $\ce{NH4Cl}$ and $\ce{NH4OH}$ to precipitate $\ce{Al(OH)3}$, mentioned that the solubility of this precipitate ...
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1answer
38 views

What product is created in a zinc - nitrate reaction? [closed]

Question: Place 2 mL of Nitric acid in a test tube and add a small piece of Zinc turning I thought that the overall net ionic equation would be: $$\ce{Zn + 2H+ -> Zn^2+ + H2}$$ Is this correct? ...
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How does the surface to volume ratio of ions and their distribution in solution compare to that of suspended nanoparticles in nanofluids?

I am interested in understanding the heat transfer capabilities of fluids. Nano-fluids are suspensions of nanoparticles (1-100nm sized particles) in a base fluid, often water, oil or glycol. These ...
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1answer
68 views

Hydration vs Dissolution

While revising Thermodynamics and Thermochemistry from revision material published by Arihant publications I encountered the following mentioned statement. During dissolution, the physical state of ...
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1answer
5k views

Concentration uncertainty due to volume measurement with cylinder

(All volumes were measured using a measuring cylinder which has a $\pm\pu{0.5 cm3}$ uncertainty) You have a $\pu{50 cm3}$ of $\pu{0.5 M}$ solution to begin with You then make a $\pu{0.4 M}$ ...
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0answers
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Why in positive deviation from Raoult's Law partial vapour pressure of a liquid component is greater than what is predicted by Raoult's Law?

When my teacher was teaching me positive deviation from Raoult's Law, he told me that in this case $P_{solution}>P_A^°χ_{A} + P_B^°χ_{B}$ He told that here the solute-solvent interactions are ...
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1answer
386 views

What is the concept behind the calculations for the dilution of solutions?

I'm interested in the concept behind this computation and was wondering if anyone could give me some pointers or hints. I've prepared $0.28~\mathrm{L}$ solution of $0.8500~\mathrm{M}$ of $\ce{Al(NO3)3}...
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Osmotic Pressure of Aqueous Solution

The osmotic pressure of an aqueous solution at $25$ Celsius is $92.0$ $kPa$. Calculate the boiling point of the solution. (Assume that the density of the solution is $1.0$ $g/mL$, ignore the mass of ...
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2answers
157 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....
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1answer
4k views

Is there a certain amount of titrant that is ideal?

For an AP chem lab dealing with determining the amount of citric acid in orange juice by titrating with NaOH, one of the discussion questions goes like this: Choose an amount of beverage to be ...
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Why does the non-volatile solute go into the liquid part of the the solution when a solution containing non-volative solute is freezed?

My teacher gave the following diagram in the class notes. He said that when a solution containing a non-volative solute (for e.g. a solution of $\ce{NaCl}$ in water) is freezed, then there will be ...
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1answer
112 views

Why is change in volume of the solution zero in case of an ideal solution?

In my textbook it is written that $ΔV_{mix} = 0$ for ideal solutions i.e. $V_{solution} = V_{A} + V_{B}$. But why is this true? There is literally no explanation in my textbook as to why this is true. ...
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2answers
56 views

How to run electrochemical tests on Microorganism (bacteria in a medium)?

I am trying to run some electrochemical tests(e.g.CV (Cyclic Voltammetry) & EIS (electrical impedance spectroscopy)) using half cell configuration on micro-organisms (e.g.bacteria). The bacteria ...
4
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1answer
179 views

Polyprotic acids and bases

I just have a question on how you handle polyprotic bases. Question: Show how oxalate ion can be a polyprotic base My answer: My question is whether we stop doing the reaction until the oxalate ion ...
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1answer
77 views

Depression of the Freezing Point

Recently we learnt that there is a depression in the freezing point when a non-volatile solute is added to the solvent. Our teacher explained this phenomenon with a graph where the vapour pressure of ...
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2answers
140 views

A solution is cloudy at lower concentration and becomes clear at higher concentration. Why?

This might be just an "everyday life science" question. I am a university professor but not in Chemistry so please educate me. Today I was adding some floor cleaner formula to water as ...
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0answers
144 views

Will potassium permanganate react with ferric chloride?

I came across a question : Which of the following compound does not decolourise an acidified solution of $\ce{KMnO4}$? Answer was: After doing a bit of research I found that $\ce{KMnO4}$ oxidises $\...
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1answer
2k views

Why can we not use water instead of blank control solution in enzyme catalysis with Peroxidase experiment?

I have to do a lab about enzyme catalysis with peroxidase in my chemistry class. We are to use the blank control solution in the experiment. My question is, why can we not use water instead? I did ...
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2answers
4k views

What does all chromatography have in common?

We're learning about chromatography in class, and I'm confused about all the different types (e.g. those that separate liquid-liquid solutions vs. those that separate liquid-solid solutions vs. those ...
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1answer
126 views

Can we compare the vapour pressure of solutions whose concentrations and temperature is known?

If we have some solutions, in which we know the temperature and concentration of the solute particles, can we compare their vapour pressures? Original question: Which solution has the highest vapour ...
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2answers
264 views

Azeotropic mixtures and Raoult's Law

So I find this everywhere: "Mixtures showing large deviations from Rault's law form azetropic mixtures at specific compositions" My questions are: (a)Why is it so?Why deviation from Raoult's ...
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1answer
53 views

Does the composition of a solution keep changing when being boiled? [closed]

The mole fractions of the components of vapours aren't the same as those of the liquid-liquid solution (unless the solution is azeotropic), this implies a change in the composition of the liquid ...
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0answers
56 views

Henry's Law and "Gases in Vapour Phase"

I found the following definition of Henry's Law in my textbook: "The partial pressure of the gas in vapour phase is proportional to the mole fraction of the gas in the solution." My ...
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1answer
375 views

To calculate total vapour pressure of a solution

Question: 1 mole each of A and B were mixed to obtain an ideal solution of which one mole went to the vapour phase at equilibrium. If $P°_\mathrm{A} = \pu{100 torr}$ and $P°_\mathrm{B} = \pu{900 torr}$...
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1answer
61 views

Finding the concentration from a dilution

This must be a very basic question but I have gotten confused over it. How would I find the concentration of each component of the reaction for each experiment from this data? I am guessing it can’t ...
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1answer
66 views

Confusion in solubility expressions in Henry's Law

While reading about Henry's law and solubility I frequently come across two relations: $C = k_{h}P$ (c = concentration of a dissolved gas) $P = k_{h}x$ (x = solubility/mole_fraction) What is the ...
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0answers
13 views

What is an effective coagulant/flocculant for an acidic solution?

The acidic solution is a mixture of dissolved ammonium sulfate and mono-ammonium phosphate (pH about 4.5-4.8) along with an inorganic sludge with a similar consistency to clay I am looking to remove ...
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0answers
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DIY lipid nanoparticles

I, and a number of friends, take a bunch of supplements that are polyphenols and often flavin-oids, -ols or -es; also numerous carotenoids. Examples include quercetin, luteolin, fisetin, curcumin, ...
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1answer
2k views

Equation to find specific gravity (or density) from a solution of sugar and water

Is there an equation or simple way to calculate the final density of a solution made from x grams of sugar and y liters of water? And would it work in reverse? if we have y liters of water at z ...
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1answer
263 views

Is mixture of ammonium hydroxide and ammonium nitrate a buffer solution? [closed]

Is a mixture of $\ce{NH4OH}$ and $\ce{NH4NO3}$ a buffer solution? I have seen some examples with $\ce{NH4OH}$ and $\ce{NH4Cl}$ but never $\ce{NH4NO3}$.
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649 views

How do I prepare citric acid solution (from anhydrous powder) of accurate concentration, given that the solution volume expands when water is added?

I attempted to prepare saturated citric acid solution from anhydrous powder. According to online data, the solubility limit was 59.2 w/w at 20 °C, i.e. 59.2 g citric acid in 100 mL water. To ensure ...

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