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

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4
votes
0answers
21 views

How do I make a dysprosium chloride solution from dysprosium oxide?

I know that dysprosium oxide is insoluble in water. I was told that I need to add concentrated $\ce{HCl}$ to the compound and then evaporate the $\ce{HCl}$ off. From looking at the reaction equation, ...
2
votes
0answers
16 views

Preparing CdSe electrodeposition bath

What is the best way of preparing an aqueous solution containing 5 mM $\ce{CdSO4}$, 1 mM $\ce{SeO2}$, 0.5 M $\ce{Na2SO4}$ and adjusting pH to 3 by adding 0.5 M $\ce{H2SO4}$? What is the ...
2
votes
2answers
35 views

What are the effects of adding water to a system at equilibrium?

Given the reaction $\ce{NaCl~(s) <=> Na+~(aq) + Cl^{-}~(aq)}$. $\ce{NaCl}$ is added to water and equilibrium is reached. Does the reaction shift to the left/right/not shift at all if more ...
5
votes
1answer
51 views

What is the white substance left behind after boiling down water

I was boiling down water in a stainless steel pot as an experiment the other day. When the water was completely vaporised, a white substance was left behind on the bottom of the pot. I tried rubbing ...
1
vote
1answer
25 views

concentration of magnesium chloride solution in an experiment?

I want to make a solution with 30% concentration of Magnesium Chloride and I need a total of $72~ \text{kg}$ of solution. the magnesium chloride is not pure, the composition of it is ...
0
votes
1answer
59 views

Dissociation of different compounds?

What would be the dissociation of Hydrosulfuric acid in the presence of water? I was thinking that Hydrosulfuric acid or $\ce{H2S}_{(aq)}$ would form $\ce{2 H+}$ and Sulfur ions. With this logic, I ...
2
votes
1answer
53 views

Why can't alcohols turn blue litmus red?

I came across the fact that alcohols cannot turn blue litmus red. The fact confuses me as they are acidic and acids do turn blue litmus solution red. What prevents alcohols from turning blue litmus ...
1
vote
1answer
36 views

I have 100mg of a proteinase K lyophilized powder and I need to make it to a working concentration of 25mg/mL

So I know that I need to add $4~mL$ of solution to this powder, which will give me a concentration of the enzyme at $25\frac{mg}{mL}$. What I do not understand is how to decide how much of each of ...
2
votes
1answer
46 views

Prepare 1 liter of 28% NH3(aq) solution from 1 gal of %10 NH3(aq)

I have one gallon of commercial, surfactant free, ammonium hydroxide solution that I would like to use to prepare a concentrated solution. I have two options as I see it, and I am still getting into ...
3
votes
3answers
47 views

Can there be more solvent in a solute?

Something I know that leads to this question: water dissolved in ethanol. It might sounds weird to say water as a solute. Textbooks always says that solvent is the one present in larger ...
2
votes
2answers
32 views

Should the volume of a solute be factored into the volume of a solvent when preparing a substance of a certain molarity?

Upon being asked to prepare a solution of a given molarity from a solution with high concentration I was confused whether or not I should factor in the volume taken from the high concentration ...
1
vote
2answers
52 views

Which formula is correct for calculating the heat of dissolution?

I want to calculate the energy change when a solute is dissolved in water. I know that I can achieve this by using the equation $q=mc \Delta T$. My question is does the mass ($m$) change with the ...
3
votes
1answer
40 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. ...
0
votes
1answer
24 views

Equilibrium Constant of a Salt knowing the solubility

Calculate the equilibrium constant in $\ce\\M ^ 3$ of the heterogeneous system in aqueous solution: $\ce{CaF2 \leftrightarrows Ca^{2+} + 2F-}$ Knowing that the solubility of the salt is $15.9 ...
2
votes
1answer
38 views

Why does the ionic product of water remain constant after addition of non-neutral solute?

In my textbook, it is given that the ionic product of water $K_w$ remains constant even when a non-neutral solute such as an acid is added to it. $$K_w=\ce{[H3+O][OH- ]}$$ When a strong acid is added ...
2
votes
1answer
61 views

How is tea affecting water's color?

Black tea is an amazing product of the green tea leaves. A recent study has proven that; The anion profile for the tea solution indicated that oxalate and citrate were the major anions detected. ...
0
votes
1answer
53 views

How is the dissolution of acetic acid that makes its aqueous solution a poor electrolyte?

I'm having a difficulty understanding the following quote from Wikipedia - Dissociation: Acetic acid is extremely soluble in water, but most of the compound dissolves into molecules, rendering it ...
1
vote
2answers
29 views

How can an insoluble compound be a strong electrolyte

Here's a quote from Petrruci General Chemistry (pg. 160): Silver chloride, $\ce{AgCl}$ is an insoluble ionic compound. When $\ce{AgCl}$ dissolved in water, it is 100% dissociated into ...
0
votes
2answers
64 views

Why is water a poor solvent for organic molecules?

Few organic molecules dissolve in water but why is this the case?
11
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5answers
3k views

Why is water “the universal” solvent?

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 is true ...
1
vote
1answer
27 views

What other factors can make a compound dissolve into water?

I am doing some homework just right now, and I encountered this problem. I know that the polarity of the water molecules allows them to be a solvent for a variety of polar species or even species ...
3
votes
0answers
66 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 ...
2
votes
1answer
36 views

Why is hydrogen bonding more significant than any other interaction between dipoles?

Solvents can be categorized as polar and protic. I understand that to be protic there had to be a significantly polar bond involving a hydrogen atom. However, how is the a hydrogen bond different in ...
4
votes
1answer
42 views

Does Iron (III) Sulfate react with copper?

As my understanding, there should be an oxidation-reduction reaction: $$ \ce{2Fe^{3+} + Cu \rightarrow 2Fe^{2+} + Cu^{2+}} $$ However, I always see the process using $\ce{FeCl_3}$ to etch ...
-2
votes
1answer
29 views

Where does the energy in the exothermic reaction of CaCl2 with water come from?

Today I created $1~\mathrm{M}$ aqueous solution of $\ce{CaCl2}$ and realized that the water before the mixture had a temperature of 23.4 Celsius degrees. Then I added the $\ce{CaCl2}$ and the ...
3
votes
1answer
45 views

Best x-ray doppant?

An X-ray computed tomography scanner has been used in an attempt to look at the pore space of a limestone rock sample (a carbonate, $\ce{CaCO3}$) saturated with a 12 wt% Sodium Iodide ($\ce{NaI}$) ...
1
vote
2answers
44 views

How to predict the solubility of an organic compound in different kinds of solvents? [duplicate]

How is it possible to know whether a particular solvent will dissolve in a particular kind of solvent, i.e. organic, polar, protic...? Are there any indicators to look for in molecules or elements ...
1
vote
1answer
32 views

Preparation of iodine solution

How to prepare $\mathrm{0.1M}$ $\ce{I_2}$ solution. I have found in books that it should be prepared in $\ce{KI}$ solution but none of them explains why? Please explain in detail not just the ...
0
votes
1answer
28 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 ...
0
votes
1answer
52 views

What happens when oxidizing Ni(OH)2 with a strong base?

In an aqueous solution, Nickel oxyhydroxide is oxidised with a 1:1 ratio of aqueous Sodium hydroxide. My goal is to produce Nickel oxyhydroxide ($\ce{NiOOH}$). Strong Base: $\ce{NaOH + H2O ...
0
votes
1answer
30 views

chlorine formed in hydrochloric acid

Is it plausible that free chlorine could be formed in concentrated hydrochloric acid. The background to this is that I have bought some 30% HCl to remove calcium carbonate scale from a reverse ...
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2answers
38 views

What causes Starch's lump creation when solvent (butter/water/oil) is added and how to prevent them

When liquid(water/butter) is added to starch lumps of starch are formed. Which are completely dry from inside. Adding more solvent doesn't seem to help therefore it is not a case of saturated ...
0
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0answers
32 views

density of potassium bromide

I'd like to know the density and viscosity of aqueous KBr at varying concentrations and at varying temperatures. I was able to find this data at 20 degrees C in the CRC Handbook for Chemistry and ...
4
votes
1answer
146 views

Will I get bromine by electrolysis of the brine from the Dead Sea?

I know that electrolysis of a saturated solution of sodium chloride with an inert anode (eg., graphite) is a handy way to obtain pure chlorine. I have a sample of saturated salt solution from the Dead ...
8
votes
2answers
2k views

If caffeine is an alkaloid, why is coffee acidic?

I have just put together on my mind these two facts: caffeine is an alkaloid and brewed coffee is slightly acidic (pH = 5). My Biology teacher and my Chemistry teacher could not elaborate satisfying ...
2
votes
2answers
120 views

Why do acids ionize in solution if they are covalently bonded?

Maybe I am wrong, but I thought acids were covalently bonded since hydrogen doesn't form ionic compounds. For example, wouldn't $\ce{HCl}$ look like: Since the electrons are shared, why does it ...
0
votes
1answer
92 views

Buffer action of borax

How does a mixture of borax and boric acid act as an acidic buffer? Please also describe the mechanism of its buffer action.
1
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0answers
55 views

pH of calcium carbonate in ammonium chloride solution (theoretical; not a calculation question)

Consider calcium carbonate saturated in 1.0 M ammonium chloride solution. I have calculated the pH of this solution analytically (with mass and charge balance) to be 6.92. Now, how would the actual ...
1
vote
1answer
31 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 ...
1
vote
1answer
87 views

Magnesium powder mixed with CuSO4 solution

$\ce{Mg}$ powder is stirred into $\ce{CuSO4}$, what is the balanced molecular equation for this reaction ? I have $\ce{Mg + CuSO4 -> Mg2SO4 + Cu}$. Also, is the ionic equation the same as the net ...
3
votes
3answers
99 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 ...
2
votes
1answer
94 views

Net ionic equation with only aqueous ions

When you turn a balanced equation into a net ionic equation, you ignore all the ions that are spectator ions (aqueous on one side as well as the other). You only write the solid and the aqueous ions ...
0
votes
2answers
44 views

How to verify the accuracy of a pH meter

One suggestion I received is that I prepare a solution of a known activity and probe the solution with the pH meter. The problem I see with this is that any error in solution preparation can lead us ...
0
votes
1answer
62 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?
0
votes
1answer
180 views

Removing HCl from water

I have water contaminated with dissolved chlorine: $\ce{H2O + Cl2 <=>HCl + HOCl}$ During electrolysis, this is an issue. These are my products: $\ce{NaCl + H2O ->T[electrolysis] NaOH + Cl2 ...
4
votes
1answer
52 views

Determining redox half-reactions of single displacement reactions

For the following double displacement half reaction, the half reactions can be determined easily using the oxidation numbers. $$\ce{MnO_{4(aq)}^{-} + IO_{3(aq)}^- -> MnO_{2(s)} + IO_{4(aq)}^-}$$ We ...
4
votes
1answer
180 views

Is 4-nitrobenzaldehyde or 4-aminobenzaldehyde more likely to be hydrated?

Of 4-nitrobenzaldehyde and 4-aminobenzaldehyde, which has the higher $\ce{K_{eq}}$ of hydration? $\qquad \qquad$ Steric factors can likely be ignored in this problem since we are dealing with ...
0
votes
2answers
79 views

How to calculate the solubility product for PbS from galvanic potential?

Knowing that at 25°C the following galvanic cell: $$\ce{Pb~|~Pb(NO_3)_2~1M~||~PbS~saturated~|~Pb}$$ shows an $\mathrm{EMF} =0,413~\mathrm{V}$, find the $K_{sp}$ of $\ce{PbS}$. My Approach This ...
1
vote
0answers
24 views

Identifying probable compound using its colour & reactants

This is quote from OxyChem document on Hypochlorites: Steel tanks in caustic soda service become passivated with a gray-black film forming on the metal. Thereafter, caustic soda at less than ...
1
vote
2answers
34 views

Can citric acid protonation produce benzene and water

Is this reaction possible: $\ce{C6H8O7 + 12 H3O -> C6H6 + 19 H2O}$? Considering that the $\ce{H+}$ can be induced by ionization of the citric acid solution the benzene can be produced in this way?