Questions tagged [aqueous-solution]

For questions relating to compounds dissolved in water and resulting reactions and acid-base equilibria.

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2
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1answer
475 views

How can I carry out a titration to identify mercury in wastewater?

First, I would like to do a some form of extraction to only get the mercury, then followed by a titration to identify the concentration or the presence of mercury.
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3answers
6k views

Electrolysis of aqueous lead nitrate

When going through one of my chemistry textbooks, I saw that the electrolysis of aqueous lead nitrate led to oxygen being formed at the anode and lead being formed at the cathode. However, in school, ...
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2answers
468 views

HF and water miscible?

According to Wikipedia, HF is miscible with water. But isn't hydrogen fluoride a gas at RT and a sensible pressure? What would happen if you just kept adding more HF gas to some water?
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1answer
444 views

Zinc Picolinate - Positive, negative or neutral charge?

I'm going to be using a finings agent with a positive charge to remove negative trub from a solution (beer). I would like to keep some chelated zinc in the solution - ideally zinc picolinate - so ...
2
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1answer
39k views

How do I prepare a 5N HCl solution?

I am trying to make 5N $\ce{HCl}$ solution. So far I understood that you need to get the molecular weight (36.5) and divide it by the number of $\ce{H+}$ that react in the acid-base reactions. The ...
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2answers
3k views

Heat when dissolving solutes in water

Why do certain solutes dissolved in water release heat and other solutes absorb heat?
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5answers
21k views

How to dissolve steel without affecting aluminium alloy

Disclaimer: I have very limited knowledge of chemistry My problem is the following: I have motorcycle part made from some sort of Aluminium alloy - most probably 6005, 6061-T6 or 7005. And inside of ...
2
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2answers
338 views

Does removing solution affect a supersaturated solution

Given a mixture of: a saturated solution of a solute in a solvent together with excess of the solute compound as crystalline material. If one were to change the bulk composition of the mixture by ...
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3answers
47k views

Volume required to dilute solution for a pH change

A $\pu{100 mL}$ solution of $\ce{NaOH}$ has a $\mathrm{pH}$ of $13$. What volume of water in $\pu{mL}$ must be added to change the $\mathrm{pH}$ to $11$? My steps: Begin by calculating conc. of $[\...
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1answer
2k views

Evaporation of a mixture of salts

I was wondering what happens when you boil dry a solution of several salts for example a solution of KCl and NaNO3. Since the ions dissociate I was wondering if the ions would combine randomly upon ...
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1answer
411 views

How much water has boiled off when precipitation begins? [closed]

Here's a challenge problem I created! None of my students could get it; can you? $25$ grams of table salt (NaCl) is dissolved in $150$ grams of water. The temperature of the solution is raised to its ...
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1answer
13k views

What is a complete reaction?

For a lab assignment, I combined $\pu{10 mL}$ of $\pu{1 M}$ sodium sulfate solution with $\pu{10 mL}$ of $\pu{1 M}$ calcium chloride solution. The ionic equation I came up with is: $$\begin{multline} ...
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1answer
50 views

Two chemistry inquiries [closed]

Here is my second question, I know 1000 grams of water is 1 liter. But does the density affect the result? What if the substance is mercury? When you add seed crystal in to a supersaturated solution, ...
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2answers
1k views

Problems with precipitation of transition metal solution

I am trying to make a solution of "trace elements"--primarily transition metals-- for use in biological media; bacteria require elements like Cobalt, Molybdenum, iron, etc. in trace amounts. I am not ...
6
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1answer
2k views

How is an aqueous Ag+ the same as [Ag(H2O)2]+?

$\ce{Ag^{+}_{(aq)}}$ can be written as $\ce{[Ag(H2O)2]+}$ but how would you know that it bonds with 2 water molecules? I don't get when ligands randomly form 6, 4, 2 bonds.
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1answer
217 views

How do ligands and coordination complexes work in this case with copper (II) chloride?

What happens when Ammonia is added to an (aq) solution of copper II chloride? $\ce{CuCl2 + NH3 ->\; ?}$ I know that ligands bond with metals to form ion but I'm not sure about how they work in a ...
4
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1answer
832 views

Does supersaturated caffeine polymerize?

I tried preparing a supersaturated solution of caffeine by mixing anhydrous caffeine powder with water in a thin Turkish tea glass and heating it up over a candle (desperate times...). This worked ...
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1answer
281 views

Reasons behind the different colors of a solution containing Iodine

Q) Iodine dissolves in a variety of solvents, forming solutions that are purple, brown or any intermediate shade. This property is due to: Hydrolysis of iodine Formation of crystalline adducts Charge ...
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3answers
2k views

Are refractive or density based Brix meters better for use with alcoholic drinks?

Assume that somebody wants to measure the sugar content of a liqueur. It seems that there are two types of Brix meters for it, ones which use the solution density and ones which use refraction of ...
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1answer
1k views

Calculating approximate pH of polyprotic acids

When I took up ionic equilibria and titrations after a long break, I found it hard to solve the questions regarding pH calculations of polyprotic acds. Consider these two questions as examples:- ...
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2answers
10k views

Can two precipitates form in a precipitation reaction that starts with only two compounds in water? [closed]

Can two precipitates form in a precipitation reaction that starts with only two compounds in water?
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2answers
11k views

What is the process of turning ionic silver solution into colloidal silver solution?

I've looked at a number of different colloidal/ionic "silver solution generators." After my research I'm under a few impressions and if they're wrong please let me know. I also am wondering what ...
4
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1answer
185 views

Could micrograms of polonium really change the viscosity of a whole teapot?

I was reading How radioactive poison became the assassin’s weapon of choice and it opens describing how The men eventually left, and Andrade cleared the table. As he poured the remaining tea away, ...
3
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1answer
2k views

Decomposition of iron(III) acetate?

I recently asked about the synthesis of iron (III) acetate. I want a rather concentrated solution to use as a calligraphy ink (which will be dissolved in alcohol/water). Will it be okay to heat the ...
6
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1answer
2k views

Can I synthesize iron acetate like this?

The oxidation state of the iron doesn't matter too much; I am just trying to make an attractive red-brown ink. Here are some instructions I prescribed to a friend. Here's an approximately decent ...
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2answers
5k views

How to liquefy or extract water from superabsorbent polymer

I am finding a good way to liquefy or extract water from superabsorbent polymer. From what I remember it was salt that can liquefy it. Since salt when dissolve will have sodium cation and there for ...
6
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1answer
4k views

Calculating Standard Gibbs Energy of Dissolution

The solubility of mercury (I) iodide is $\mathrm{5.5\ fmol/L}$ in water at $25\ \mathrm{^\circ C}$. What is the standard Gibbs energy of dissolution of the salt? The reaction is $$\ce{Hg2I2(s) -&...
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4answers
6k views

Why is zinc deposited on copper when boiling an aqueous zinc sulfate solution?

I did an experiment where I dissolved 30 grams of zinc sulfate in water and boiled it with strips of solid zinc metal and strips of copper metal and a layer of zinc was deposited on the copper. I ...
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0answers
107 views

Isoelectric point pH, mV, for a metal oxide nanopowder

I'm trying to make a solution of $\ce{TiO2}$ that will coat stuff in as dense a monolayer as possible. To do so, I'm using nano sized $\ce{TiO}$ particles and trying to get them to get as close to ...
3
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1answer
144 views

Isoelectric pH of colloids?

How did we derive the relation between the isoelectric pH and the dissociation constants for the amino and carboxyl groups on zwitterionic amino acids. $$pI=\frac {pK_{a1}+pK_{a2}}{2}$$ where $$\ce{...
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1answer
25k views

How to calculate molality, molarity and mole fraction given density (g/mole)?

Calculate the molality, molarity and mole fraction of a $\ce{CuSO4}$ in a 17% m/m aqueous solution (density of the solution is 1.367 g/mole) I did .17 * 1.367 to find grams of $\ce{CuSO4}$ and .83 * ...
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1answer
6k views

Are these the correct and complete net ionic equations?

So I have several descriptions of reactions and I have to give the net ionic equation. Are these just the equations or are they the proper net ionic ones? Solid calcium is added to warm water. $$\ce{...
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2answers
9k views

How is iron(III) chloride changed from solid to solution?

I'm conducting an experiment using iron(III) chloride in aqueous solution, but am also aware that it's usually a solid. How is iron(III) chloride experimentally converted to a solution? And can you ...
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1answer
993 views

How do I write the complete and net ionic equations for Insoluble compounds?

So, I was doing my homework and had to write out the complete equation and net ionic equation for a combination of Lead (II) Iodate and Sodium Hydroxide. So my equation is given as: $\ce{Pb(IO3)2_{(...
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2answers
20k views

Electrolysis of aqueous copper (II) nitrate

There are two copper blocks sitting in the $\ce{Cu(NO3)2 (aq)}$ solution, a battery is attached onto both of them, providing enough energy to start the reaction. Since solid pieces of copper are ...
2
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1answer
461 views

Can we extract KI from Lugol solution?

I want to extract the $\ce{KI}$ component of the Lugol solution, is there a method to do it? If not, how can I make a $\ce{KI}$ solution?
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4answers
6k views

Why is it not dangerous to dissolve NaCl?

$$\ce{H2O~(l) + NaCl~(s) ->[\Delta] Na+~(aq) + Cl^{-}~(aq)}$$ When table salt is placed in water, it dissolves due to the polarity of water molecules. When solvation takes place, negatively polar ...
4
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1answer
463 views

How does the composition of ice differ from that of water in a partly frozen solution?

Take any solution, then start freezing it at sufficiently low temperature. Soon a small amount of ice forms. I'd like to know how the composition of dissolved salts and gases in the bit of ice differs ...
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1answer
3k views

Notation “5% solution”

What does 5% aqueous solution of glucose mean? Note that it's just 5% and not 5%w/w. Do we assume it to be w/w? The question is If the osmotic pressure of 5% aqueous soultion of glucose is $\pi_1$ ...
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1answer
416 views

Thermodynamics behind Deliquescence?

The phenomenon of deliquescence wherein a water soluble substance absorbs water from atmosphere and dissolve in it forming a saturated solution, has thermodynamic roots. I have read the fact that the ...
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3answers
26k views

Why do salts such as NaCl dissolve?

If we look at solubility of salts in water, we are told that they disassociate, because the positive $\ce{Na}$ ion is attracted to the partially negative oxygen in water and the negative $\ce{Cl}$ is ...
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0answers
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Why Add Salt to Vinegar to Clean Pennies? [duplicate]

One common cure for dirty pennies is to put them in vinegar and salt. The vinegar should react with the copper oxide on the penny in the following way: $\ce{2CH3COOH + CuO -> (CH3COO)2Cu + H2O}$ ...
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1answer
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What is the colloidal osmotic pressure?

The oncotic pressure or colloidal osmotic pressure is the osmotic pressure developed due to the presence of colloids in a solution. But since the colloids are not true solution, why should the ...
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2answers
12k views

Azeotropes and separation by distillation?

I have just recently learnt the theory of fractional and normal distillations and the basics of maximum and minimum boiling azeotropes. Most books say that the components of the mixture forming an ...
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2answers
184 views

Would dissolving a salt and letting it sit for 48 hours have an effect on the solution?

If one were to dissolve magnesium citrate (about $100~\mathrm{mg}$) in water (about $70~\mathrm{ml}$) and let the solution sit for 48 hours, would the solution be exactly the same as one dissolved and ...
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1answer
843 views

Crystallization of solutions and liquids

The process of crystallization of a liquid or any solute occurs when its concentration exceeds the maximum concentration which the solvent can carry or when the temperature drops below the freezing ...
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1answer
166 views

How to solve this contradiction?

I am getting confused about this the more problems I do on it. My understanding was that only strong acids and strong bases will react to produce water and a salt. Something like this: Molecular Eq: $\...
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1answer
4k views

Vapour pressure varing with molality

Vapour pressure of water at 298 K is 0.025bar. Following solutions are prepared at the given temperature whose molality I have calculated to be, Solution A 0.56m urea dissolved in 178.2g of water ...
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2answers
10k views

Which one is nitric Acid, HNO3 by itself, or when it is included in H2O?

This is a quote from my Chemistry textbook: Nitric acid ionises according to the following equation: $$\ce{HNO3(l) + H2O(l) -> H3O+(aq) + NO3- (aq)}$$ I know that the formula for nitric acid ...
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2answers
1k views

Time to effervescent an effervescent tablet

Say I have an effervescent tablet and I put in water. I thought that if I break the tablet in two halves it would dissolve quicker than with the whole table (without breaking), but it actually takes ...