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

learn more… | top users | synonyms

1
vote
1answer
39 views

What will be the reaction between tin (II) chloride and copper (II) chloride?

I just tried conducting an experiment during lunch today. Now, I calculated this reaction 4 days ago dealing with electrochemistry, $$\ce{SnCl2 + CuCl2 -> Cu(s) + SnCl4}$$ Theoretically, I got ...
1
vote
3answers
22 views

w/w % to molarity

After reading a number of explanations about it after googling, I'm a bit confused on this. Some explanations are doing it using a solution density, others aren't, though most are. On one site it's ...
0
votes
0answers
24 views

Special effects: using non-toxic solutions to create colors

I'm looking for a non-toxic solution to create low budget special effects without using digital effects. An actor ($175\: \mathrm{cm}$ tall) could: wear a particular kind of clothing? be coated ...
1
vote
1answer
31 views

How to filter out magnesium acetate (a soluble salt) quickly and cheaply from water

I am conducting an experiment that involves reacting a weak acid and a weak base to form water and a salt with this overall equation $$\ce{Mg(OH)2(s) + 2CH3COOH(l) <=> 2H2O(l) + ...
1
vote
1answer
120 views

Do you include the “10 H2O” in the formula for borax?

When you calculate the mass of borax needed to make up a standard solution, do you include $\ce{\cdot 10 H2O}$ in the formula for borax? Why or why not?
0
votes
0answers
36 views

Hydronium Salts

When it comes to solids, hydroxide salts are quite abundant. There is $\ce{Mg(OH)_2}$, $\ce{NaOH}$, $\ce{CsOH}$, $\ce{Ca(OH)_2}$, and $\ce{Fe(OH)_3}$, just to name a few. However, (correct me if I'm ...
1
vote
1answer
38 views

Freezing Point Depression Problem

Assuming an ideal solution, which of these 0.10 M solutions would have the least freezing point depression? $\ce{HCl}$ $\ce{NaBr}$ $\ce{KNO_3}$ $\ce{MgSO_4}$ They all produce ...
2
votes
1answer
31 views

What solutes will give the largest reduction in volume when dissolved in water

This question is inspired by another question. If you take some common salt (NaCl) and some water and mix them, then the volume of the solution is less than the volume of the constituents. I did ...
-1
votes
0answers
23 views

How do you find mass percent composition based on molality?

You take $20.0~\mathrm{g}$ of a sucrose and $\ce{NaCl}$ mixture and dissolve it in $1.0\ \mathrm{L}$ of water. The freezing point of this solution is found to be $0.426~\mathrm{^\circ C}$. Assuming ...
1
vote
1answer
47 views

Unique Solubility Expression for Sulfide Salts

While looking at aqeuous $\ce{K_{sp}}$ values in the back of my textbook, I noticed that there is a asterisk by all of the sulfide compounds (such as $\ce{HgS}$), and the asterisk says, "For a ...
1
vote
1answer
21 views

Mixing a Tagged Sample of Lead Iodide with another Iodide Salt [closed]

A sample of sparingly soluble $\ce{PbI_2{(s)}}$ containing radioactive $\ce{^{133}I}$ is added to 0.10 M $\ce{KI_{(aq)}}$ and stirred overnight, what happens? I The radioactivity of the liquid phase ...
0
votes
1answer
41 views

What actually happens when citric acid is added to a highly alkaline soap solution?

A few days ago I made an experiment. I diluted a few small chunks of bar soap with 20 ml of water. I then measured the ph of the solution which was around 10. I then added a tiny amount of citric ...
1
vote
1answer
24 views

Can one predict the entropy change for aqueous phase reactions without calculation?

I have seen several sources that claim aqueous solutions always have more entropy than pure liquids or solids, however, some aqueous ions have negative standard entropy. This opens the possibility of ...
3
votes
2answers
64 views

What does solubility limit mean in practical terms?

I am not really a chemist guy so please bear with me. Glycerol monolaurate has an upper limit of solubility in water of 20 μg/mL, which is enough for my experiment. Does this mean that no matter how ...
1
vote
0answers
39 views

Poor aqueous solubility of chloroazodin

Below is the structure of chloroazodin: Why is chloroazodin poorly soluble in water? It has multiple amine and imine nitrogens, all of which appear to be available for hydrogen bonding, and thus it ...
2
votes
3answers
230 views

What is the compound called when it is in solution?

When a compound precipitates out of solution, for example Calcium Carbonate from a water solution, it is called the precipitate. What is the same compound called before it precipitates out - once it ...
1
vote
0answers
26 views

Will bases typically precipitate silver atoms from silver ions?

In class I learnt that one can dissolve many substances using acid and that this can be predicted using standard electrode potentials. For example, $$\begin{align} \ce{Zn &-> Zn^{2+} + 2e^-} ...
1
vote
0answers
27 views

Why does adding PBS to a lipid+propylene glycol solution cause the lipid to precipitate?

I am trying to create an aqueous phospholipid suspension using ~50 mg of 1,2-dibehenoyl-sn-glycero-3-phosphocholine (DBPC), 13 mL of propylene glycol (PG), and 72 mL of phosphate-buffered saline ...
2
votes
0answers
18 views

Gas solubility in water and alcohol

I know that a certain gas is soluble in water but not in alcohol. How can I find the solubility of the gas in mixture of water and alcohol? Do I use a simple linear relation? The gas in question is ...
2
votes
1answer
49 views

Trying to displace iron from ferrous sulphate heptahydrate using aluminium foil but nothing has happened

I started by dissolving the sulphate into water and filtering it as I noticed there was a dirty residue lying at the bottom. (I am using ferrous sulphate that is commonly used in gardening.) I then ...
1
vote
0answers
19 views

vertically growing icicle

I made some "super" soap bubbles with my kids using the following ingredients: liquid dish soap tap water corn syrup We left the solution out over night last night here in Maine and the ...
4
votes
2answers
215 views

pH of a buffer made with H3BO3 and KH2BO3

The Problem Calculate the pH of a buffer that is 0.200M $\ce{H3BO3}$ and 0.122M $\ce{KH2BO3}$. The $K_a$ for $\ce{H3BO3}$ is $7.3*10^{-10}$ What I Tried For each of these methods, I used 0.200M as ...
0
votes
0answers
21 views

Entropy and enthalpy of hydrogen ion?

The absolute entropy of $\ce{H^+ (g)}$ is $\ce{108 kJ/mol.K}$. However, the absolute entropy of $\ce{H^+ (aq)}$ is exactly 0. Why is that? Also, the standard enthalpy of $\ce{H^+ (aq)}$ is 0, so ...
1
vote
0answers
28 views

Hydrogen Peroxide - Iron Nail Galvanic Cell?

I am planning to create a simple galvanic cell made up of common household materials. Suppose I have hydrogen peroxide (to serve as cathode), diluted in water, in one beaker, and I have a bunch of ...
0
votes
1answer
44 views

Getting the wrong pH value, according to data and online calculator

I'm doing a titration problem with a week acid and strong base, I used experiment data and an online calculator to check my answer, but my pH I calculated is a bit off. Can anyone see where I messed ...
1
vote
0answers
20 views

Why do some insoluble salts undergo slow chemical reaction instead of dissociation in water?

$$\ce{PbCl2 + H2O ->[\Delta] Pb(OH)Cl + HCl}\tag{1}$$ $$\ce{2ZnCO3 + H2O ->[\Delta] Zn2(OH)2CO3 + CO2}\tag{2}$$ $$\ce{2NiS + 2H2O → Ni2(OH)2S + H2S}\tag{3}$$ $$\ce{Hg2SO4 + H2O → HgO + Hg + ...
0
votes
0answers
54 views

How Can the System Reach Equilibrium?

Suppose that you had a generic cation, $\ce{X^+}$, that can form a hydroxide salt X(OH). In water, $\ce{X^+}$ undergoes the equilibrium $\ce{ X^+ (aq) + OH^- (aq) <=> XOH (s)}$ with a certain ...
0
votes
2answers
42 views

Molar concentration of water and pKa value

By defintion, $\mathrm pK_\mathrm a$ value is defined as $$\mathrm pK_\mathrm a = -\lg ([\ce{H2O}] K_\mathrm{eq})$$ Consider the reaction: $$\ce{HCl + H2O <=> H3O+ + Cl-}$$ The Eq constant of ...
1
vote
0answers
42 views

Getting a pH value that's not right for acid/base titration problem, after added 10mL titrant

Can someone please help me figure out where I'm messing up and getting a weird pH value? This is supposed to be after adding 10.00mL during a titration with HCl of 0.249M. It's late, and I've been ...
0
votes
0answers
44 views

Weird titration result, is this wrong like it seems?

For a titration yesterday, we used what was marked as ${0.5}$ M $\ce{HCl}$ and ${0.5}$ M $\ce{NaOH}$, adding the $\ce{NaOH}$ into the $\ce{HCl}$ that had an indicator in it. I used ${35}$ mL of ...
5
votes
2answers
54 views

How to choose the correct volumes when preparing a dilution series?

Original Question A solution of dye, Amido Black 10B dye ($10~\mathrm{mM}$, $6.165~\mathrm{g\over L}$), as-provided absorbs light much too strongly for measurement of an absorbance value. It is ...
0
votes
2answers
44 views

Autoprotolysis Constant of Water

My chemistry textbook states that $[\ce{H3O+}][\ce{OH-}] = K_w$ in all aqueous solutions, which we know of as $K_w$. However, I was wondering why this was true. The textbook states that it is true ...
1
vote
0answers
55 views

Why ethoxyethane is not very soluble in water? Since, oxygen in ethoxyethane is electronegative, as oxygen in water

If the reasons is related to polarity, I have another question. Why water is polar it is also symmetrical?
2
votes
1answer
46 views

Is it possible for a liquid chemical to have a pH value lower than its aqueous solution?

During the QC check of one of the products that we make as a company, the product had a $\mathrm{pH}$ of $10.44$ on one $\mathrm{pH}$ meter and $10.20$ on the other. (The product is a liquid, so it's ...
0
votes
1answer
42 views

Calcium sulphate soluble in water

In the volumetric estimation of calcium in a given solution as calcium oxalate.. We convert the calcium oxalate to oxalic acid by dissolving the former in hot (~70 °C) 2 N sulphuric acid solution. ...
1
vote
0answers
32 views

Mass of salt required to make a 1.2g/ml solution

I would like to make an NaCl and water solution with a density of 1.2g/ml. How would you calculate the grams of NaCl required to make a 1000ml solution? I have used density of mixture = (mass NaCl + ...
0
votes
1answer
24 views

The stability of the cupric and cuprous ions

My teacher told me that $\ce{Cu^2+}$ is more stable than $\ce{Cu+}$ in solution, but why? I think $\ce{Cu+}$ is $\ce{[Ar] 3d^10 }$ ,$\ce{Cu^2+}$ is $\ce{[Ar] 3d^9}$, why is $\ce{Cu^2+}$ more stable ...
1
vote
0answers
11 views

Dilution: Weight vs Specific Gravity [closed]

I wish to dilute 30% H2O2 (hydrogen peroxide, Specific Gravity = 1.11) to 3% using water to get 1L of final solution. Which is correct? 1) dilute 0.1kg of H2O2 with 0.9kg of water, or 2) dilute ...
0
votes
0answers
32 views

Why does final pH value of buffer solution after addition of acid not depend on amount added?

I'm brushing up and the example in my book is against my intuition. A buffer solution contains 1.0 mol/L acetic acid and 1.0 mol/L sodium acetate. The solution is at pH = pKa = 4.75. What's the ...
0
votes
0answers
36 views

Reaction on Epsom Salt in distilled water

If the Epsom salt compound is $\ce{MgSO4*7H2O}$ what reaction will happen when dissolved into distilled water? Im looking for an answer that can tell me very specific what happens with Magnesium. ...
1
vote
1answer
20 views

Figuring out highest osmotic pressure? [closed]

In preparing for an exam I'm trying to solve the following question. I'm clueless. What should I do? Which of the following water solutions has the highest osmotic pressure? 0.1 mole/kg NaCl 0.1 ...
3
votes
0answers
36 views

Spectator ions in redox reactions

I'm trying to get a fool proof way of finding the products of a redox reaction. I can do both the oxidation and reduction the half reactions. For example in the potassium permanganate with hydrogen ...
0
votes
0answers
26 views

Alkalinity (as HCO3) as estimate for C (as HCO3)

I'm working with modelling brine composition in Phreeqc. I have alkalinity data as $\ce{HCO3}$ and as $\ce{CaCO3}$, although I assume they are both calculated from the same measurement. I don't have ...
3
votes
1answer
81 views

How does increasing the ionic strength of an aqueous solution decrease the activity coefficient?

Activity is a new concept for me, so I am having a little bit of trouble understanding it. For the equation: $$\ce{aA + bB<=>cC + dD}$$ $K_c=$$\frac{[A]^a[B]^b}{[C]^c[D]^d}$. As I ...
0
votes
0answers
56 views

Freezing point depression

Three aqueous solutions are made, $\ce{FeCl2}$, $\ce{NaCl}$ and $\ce{Na2S}$ all of which have the same molarity. Which two solutions will have the same freezing point depression? a. $\ce{FeCl2}$ and ...
-7
votes
1answer
60 views

Cooling of solution [closed]

The tea with sugar added in the first problem begins to cool. You notice that the tea begins to get cloudy and a white powder begins to form on the bottom of the cup. What is happening and why does ...
0
votes
1answer
59 views

Does adding mass to a liquid (not water) increase the volume

The Question sounds stupid but i have a legit problem I mixed 1000 mL coconut water and 225 g of agar-agar to make a coconut water [CW] agar. It gave me more than 1000 ml. the medium went beyond the ...
3
votes
1answer
63 views

Does a weak buffer solution still maintain a mostly steady pH if the acid or base load it has to buffer is small?

I need to buffer the $\mathrm{pH}$ of a solution to $3.0$ using a citrate buffer. I found a recipe to make a buffer solution that would use $82\%$ of $0.1\,\mathrm M$ citric acid (monohydrate) and ...
3
votes
1answer
167 views

How does salt concentration affect corrosion rate of iron?

I have conducted an experiment where I test the affect of $\ce{NaCl}$ concentration on corrosion rate of iron. I did this in an environment were all of the iron was submerged in water and the water ...
1
vote
1answer
113 views

What's the difference between aqueous NaOH and dilute NaOH?

Dilute $\ce{NaOH}$ can be prepared by adding a suitable amount of concentrated $\ce{NaOH}$. What's the difference between "dilute $\ce{NaOH}$" and "aqueous $\ce{NaOH}$"?