For questions relating to compounds dissolved in water and resulting reactions.

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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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45 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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1answer
32 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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2answers
44 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 ...
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2answers
19 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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1answer
19 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
39 views

How much water has boiled off when precipitation begins?

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
96 views

What is a complete reaction?

For a lab assignment, I combined 10mL of 1M sodium sulfate solution with 10mL of 1M calcium chloride solution. The ionic equation I came up with is: $$\ce{2Na^+ (aq) + SO4^2- (aq) + Ca^2+ (aq) + ...
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1answer
34 views

Two chemistry inquiries

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
55 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 ...
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1answer
67 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
44 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 ...
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1answer
36 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
64 views

existence and stability of Bifluoride ion

Consider the following homework question:- Statement 1. The $\ce{HF2^-}$ ions exist in solid state and also in liquid state but not in aqueous state. Statement 2. The magnitude of ...
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1answer
51 views

Solution containing Iodine

The question is:- 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 ...
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3answers
168 views

Why do solutions become saturated?

Why can a solvent dissolve only a particular amount of solute? If we add more solute to the solution, the number of solute particles in contact with water increases. So rate of dissolution should ...
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2answers
78 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
75 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
154 views

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

I was wondering if two solids can form from two aqueous solutions? Any examples?
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1answer
100 views

What is the process of turning ionic silver solution into coloidial silver solution? (and some other related questions)

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 ...
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1answer
62 views

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

I was reading a How radioactive poison became the assassin’s weapon of choice and it opens describing how "As he [the bartender] poured the remaining tea away, he noticed that the consistency of the ...
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0answers
57 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 ...
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1answer
112 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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1answer
75 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 ...
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1answer
62 views

Need Help Calculating Standard Gibbs Energy of Dissolution

I'm trying to understand how to solve this question for my physical chemistry class, but after many attempts, I am still not getting the same solution as the solution manual. If anyone can help me I'd ...
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0answers
23 views

Isoelectric point pH, mV, for a metal oxide nanopowder

I'm trying to make a solution of TiO2 that will coat stuff in as dense a monolayer as possible. To do so, I'm using nano sized TiO2 particles and trying to get them to get as close to each other as ...
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1answer
119 views

Thermodynamics (Entropy change) of micellization?

I was reviewing the thermodynamics of micelle formation from the Wikipedia page and this book. I understood most of the arguments but micellization is supposed to be an entropy driven process with a ...
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1answer
34 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 ...
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2answers
4k 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
110 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. ...
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0answers
83 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: ...
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1answer
496 views

Electrolysis of Aqueous copper (II) nitrate

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

Can we extract $KI$ from Lugol solution?

I want to extract the $KI$ component of the Lugol solution, is there a method to do it? If not, how can I make a $KI$ solution?
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1answer
143 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 ...
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1answer
62 views

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 gasses in the bit of ice ...
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1answer
137 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 ...
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1answer
85 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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1answer
1k views

Why do salts dissolve? Why do $\ce{NaCl}$ crystals not stick together?

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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1answer
922 views

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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2answers
190 views

Sodium Hypochlorite Production Explanation

One reaction used to form sodium hypochlorite (A type of bleach) is as follows: $\ce{2NaOH(aq) +Cl2(g)->NaOCl(aq) + NaCl(aq) + H2O(l)}$ Provided the sodium hydroxide is dissolved in some ...
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1answer
194 views

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
1k 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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1answer
104 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
34 views

Acid-Base Reactions

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
516 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
236 views

Whic 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 Nitric acid formula is ...
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2answers
194 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 ...
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1answer
125 views

Why do aqueous solutions always have to be electrically neutral?

I was reviewing some analytical chemistry and stumbled upon a section that explained the imperfection of using a salt bridge. It said that the using dissimilar ions is a problem because in, for ...
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1answer
213 views

How is hydration free energy of a solute measured experimentally?

I am reading a paper (Shirts, M. R.; and Pitera, J. W. and Swope, W. C. and Pande, V. S. J. Chem. Phys. 2003, 119, 5740-5761). Near the beginning of the paper (page 5745), the authors state: ...
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1answer
137 views

How can one calculate the pH of a solution?

So, I have 1 litre of acetate buffer, and 0,1mol of oxonium ions/H3O+ is added. The task is to calculate the pH of this solution. What I was thinking: $$\ce{CH3COOH + H2O <=> CH3COO- + H3O+}$$ ...