Questions tagged [aqueous-solution]

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

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-1
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1answer
27 views

An equilibrium question involving mixing equal volumes of HCl and H2SO4

Question: Calculate the concentrations of H3O(+) and SO4(2-) in a solution prepared by mixing equal volumes of 0.2M HCl and 0.6M H2SO4. (Ka1 for H2SO4 is very large, and Ka2 for H2SO4 is 1.2E-2) Here ...
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1answer
58 views

Yellow color solution after adding sulfuric acid to a molybdate (ammonium or sodic) solution [closed]

Adding sulphuric acid (6 mL) to a molybdate solution, either sodium (15g/1L) or ammonium molybdate (10.9g/1L), gives an stable transparent solution. It's been a while since I've been able to get that ...
2
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0answers
19 views

Isomerization of phosphorylated 2-imino-1,3-dioxalanes into phosphorylated cyclic carbamates

I found a patent dating back to the Soviet Union. The patent number is 256764, and the patent describes the synthesis of phosphorylated cyclic carbamates. Here is a section of the patent, followed by ...
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1answer
183 views

Find the concentration of proton after adding a acid to NaOH [closed]

I have this simple problem that I cannot figure out though, only the first part. 100 ml of 1.0 $\frac{mol}{L}$ $NaOH_(aq)$ contains ( a ) g of NaOH. After mixing 100 ml of 1.0 $\frac{mol}{L}$ $...
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1answer
52 views

Calculate molarity given density and mass percentage [closed]

Problem Calculate molarity of a solution of $\ce{H2SO4}$ with density $\pu{1.198 g/cm3}$ and containing $27~\%$ mass of $\ce{H2SO4}.$ Answer My approach I converted the density to g/l. Then i took ...
13
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3answers
46k 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 ...
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0answers
24 views

Mixing fumed silica (ts720) into an ink procedure - advice request [closed]

I'm looking for advice on working with fumed silica (cab-o-sil ts720) to change viscosity? I've read it's quite difficult to mix to ensure it's not lumpy. I only have a small home lab set up and ...
35
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3answers
10k views

Which “exotic salt” can lower water's freezing point by 70 °C?

The Medium.com article Mars Phoenix Lander, 10 Years Later shows several remarkable images and discoveries on Mars by the Mars Phoenix Lander circa 2008. One image (shown below) shows what looks like ...
5
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1answer
468 views

Trichloride ion (c.f. triiodide ion)

While triiodide ion is commonly known, why is that trichloride ion (and its salts) almost unheard of? While it does exist according to literature, why is the stability of trichloride ion in aqueous ...
4
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2answers
18k 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 ...
7
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1answer
3k views

Why does saline have a pH of 5.5?

I am a physician and administer 0.9% NaCl in water ("normal saline") to patients frequently. The bag says it has a pH of 5.5 (compared to the human body of 7.4). I am asking why the pH is so low. It ...
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3answers
6k views

Why is sodium carbonate less soluble in water than sodium bicarbonate?

Why is sodium carbonate less soluble in water than sodium bicarbonate? If you think about their structures, the only thing that is different is that sodium carbonate has two sodium atoms, while sodium ...
2
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2answers
71 views

Does K2CO3 react in minute amounts with glassware at higher temperatures?

At a temperature of $\pu{750 ^\circ C}$, $\ce{K2CO3}$ and $\ce{SiO2}$ react with each other in substantial proportions, forming $\ce{K2SiO3}$ and $\ce{CO2}$ in the process$\ce{^{[1]}}$. We all know as ...
2
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2answers
31 views

Heat effect on diluting concentrated NaOH solution

I am an engineer in water treatment and have a chemistry question. In water treatment we dose $32\%$ sodium hydroxide solution for $\mathrm{pH}$ adjustment and there is a concern that our dosin lines ...
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0answers
60 views

The most convenient process to purify Oxalic Acid up to a high level of purity

I am set out to purify a batch of commercial oxalic acid with the aim in mind to end up with a highly pure product (starting from $\pu{4,000 ppm}$ total impurities and doing so with basic lab ...
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2answers
60 views

How Do I Determine The Strength Of Two Ammonia Solutions Using Titration Methods? [closed]

Two housewives disagreed on the strength of an ammonium cleaning agent. Housewife A thought that her brand was more effective than the brand used by housewife B. Plan and design an experiment that ...
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1answer
521 views

What is happening to my chlorine dioxide when I add too much bleach or citric acid?

I have some sodium chlorite and Chinese mystery powder which are meant to be mixed with water, then mixed together to form chlorine dioxide. I wanted to try a more food safe (and less mysterious) ...
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1answer
108 views

Why is the water solubility of CO worse than that of CO2?

I tried my best to ask SciFinder, Google, and Google Scholar the wrong questions ... I found many paper on the fitting of the solubility to some equations to be able to calculate the amount of $\ce{CO}...
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0answers
48 views

Can analytical precision be finer than a lower detection limit?

Can analytical precision be finer than a lower detection limit? For example, if the lower detection limit of an analytical method is reported as 0.010 ppm. Is it possible to have an analytical ...
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2answers
45 views

Equilibrium involving both gas phase and aqueous phase

If I have been given an equation that involves a gas-aqueous phase equilibria, how do I write the equilibrium constant? I have come across several questions that give equations having BOTH gas and ...
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2answers
8k views

Should bromine water be called a solution?

Bromine water is a reagent which is used to test for unsaturation in organic compound. It is $2.8~\%$ bromine in water. In many places, it is refer to as bromine solution. But it is observed that ...
4
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1answer
364 views

What does m± represent in the equation for mean activity of a salt solution?

I need to find the activity $a_\pm$ for a $\pu{0.0120 M}$ solution of $\ce{Na3PO4}$, and have calculated the activity coefficient, $\gamma_\pm = 0.389$. I know that $$a_\pm = \frac{m_\pm}{m_0}\gamma_\...
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4answers
83 views

How many grams of sodium phosphate must be added to precipitate as much of one ion as possible?

Problem text: Solid sodium phosphate is slowly added to $\pu{200 mL}$ of a solution containing $\pu{0.002 mol}$ of aluminum chloride and $\pu{0.001 mol}$ of calcium chloride (assuming no volume ...
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1answer
53 views

Using solubility product to determine the mass of the precipitate of a reaction

I mix together $\pu{100 mL}$ of an aqueous $\ce{NaCl}$ solution at $\pu{0.5 M}$ and $\pu{100 mL}$ of an aqueous $\ce{AgNO3}$ solution at $\pu{0.3 M}$. Assuming that the solubility of $\ce{NaCl}$ in ...
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0answers
62 views

Is there a reason why we add (CH3CSNH2) but not H2S in qualitative group analysis? [closed]

Brief question: In $\ce{Cu}$-$\ce{As}$ group analysis we are expected to add thinoacetamide to make a precipitate with sulfide. Can we use $\ce{H2S}$ instead?
4
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1answer
165 views

Can ionic compounds dissolved in organic solvent conduct electricity?

Ionic compounds dissolved in water, as an aqueous solution, can conduct electricity. Can they conduct electricity if they are dissolved in organic solvent?
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2answers
67 views

How many Cl and Na atoms per Water molecule when salt dissolves? [closed]

When salt dissolves in water the Cl and Na ions or drawn to the polar water molecules. Is it a one to one pairing? As in one Cl to the hydrogen side and one Na to the oxygen side?
4
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1answer
2k views

Does the boiling point of an aqueous solution depend on what the solute is?

Consider a situation where we have two aqueous solutions which have the same concentration (e.g. 1 M), but the solute is different. For example, one is a solution of glucose, and the other is a ...
2
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0answers
34 views

Which salts precipitate from a potassium/sodium chloride/sulfate solution?

This is not a homework question. I am not in any course of study. The following question arises from my personal curiosity. If 1 mole of sodium sulfate and 2 moles of potassium chloride are dissolved ...
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1answer
268 views

Why is maximum buffer capacity for some diprotic buffers not when pH = pKa?

According to Rajkovic et al. [1]: $$β = \frac{[\ce{H+}]}{K_\mathrm{w}} + 2.303\cdot\frac{[\ce{H+}]\cdot K_\mathrm{a}\cdot c}{[\ce{H+}] + K_\mathrm{a}}$$ where $K_\mathrm{a}$ is the dissociation ...
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1answer
36 views

Indirectly Measuring Diffusion of NO2 into Water

I am working on a data science project with the central hypothesis is that air-born pollutants can become water-born through diffusion. The example I am using as a proof of concept is $\ce{NO2}$. The ...
0
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1answer
61 views

Finding Ka of a monoprotic weak acid from pH and concentration of added sodium salt

A solution of $\pu{0.36 M}$ of the sodium salt of a generic monoprotic weak acid $\ce{HA}$ has a $\mathrm{pH}$ value of $8.782.$ $K_\mathrm{a} = ?$ Why doesn't the following formula work in this ...
1
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1answer
104 views

Calculating the biological standard potential

I have an electrochemical cell with following overall reaction: $$\ce{5 Sn^4+ + 2 Mn^2+ + 8 H2O <=> 5 Sn^2+ + 2 MnO4- + 16 H+}$$ I have defined the half reactions as: $$ \begin{align} \ce{Sn^...
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2answers
12k views

What determines whether a double displacement reaction will occur?

In normal displacement reactions, reactivity plays a large role and sometimes the reaction doesn't even happen. So is there anything limiting double displacement reactions? For example $\ce{2KI + Pb(...
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2answers
69 views

How to calculate mass of calcium fluoride that will dissolve in sodium fluoride solution?

The solubility product of calcium fluoride, $\ce{CaF2},$ is $\pu{1.46E-10 mol^3 dm^{-9}.}$ What mass of calcium fluoride will dissolve in $\pu{500 cm^3}$ of $\pu{0.10 mol dm^{-3}}$ sodium fluoride ...
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3answers
122 views

Tap water pH adjustment using citric acid

I've lowered tap water pH from 7 to 6 using citric acid. After couple of hours pH raised again to 7. What is the reason for this raise? Citric acid overcomes waters buffering feature then raise the $...
0
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1answer
45 views

Reactions of diborane, silane, methane, aluminium, boron, sodium, phosphorus trichloride, white phosphorus and iron with water at RT [closed]

How many of the following will evolve $\ce{H2}$ gas when dissolved in water under room conditions? $\ce{B2H6},$ $\ce{SiH4},$ $\ce{CH4},$ $\ce{Al},$ $\ce{B},$ $\ce{Na},$ $\ce{PCl3},$ $\ce{P(white)},$ $\...
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2answers
38 views

In a double displacement reaction, why don’t the two products reform after being dissolved in water? [duplicate]

Let’s say I have $\ce{AB (aq) + CD (aq) —> AD + CB}$. When AB and CD are dissolved in water, they get dissociated into their component ions. But why don’t they reform as AB and CD, if it is already ...
3
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2answers
102 views

Diluting 4 % NaOCl to get a 1 % solution

Assuming that one has a 1 litre bottle of liquid bleach containing $4~\%$ sodium hypochlorite. If I wish to dilute it down to $1~\%$ sodium hypochlorite (to use as disinfectant), would adding 3 litres ...
1
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1answer
47 views

Creating a 10 ppb Lead Nitrate Solution

I’m trying to make a 10 ppb Lead Nitrate solution as part of a concentration calibration step for a Beer Lambert’s Law experiment. I plan on performing a dilution in three steps. The calculations have ...
0
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1answer
67 views

Why is the solubility of calcium sulfate so low even though it is a salt? [duplicate]

What is the reason the solubility of calcium sulfate in water is so low? Compared to other salts like potassium sulfate (110 g/L) or calcium nitrate (1470 g/L) the solubility of calcium sulfate seems ...
2
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2answers
95 views

Do all metal salts in aqueous solution contain metal aquo complexes?

I know that nickel nitrate in aqueous solution contains the metal aquo complex ion $\ce{[Ni(H2O)6]^2+}$. But do all metal salts in aqueous solution contain such complex ions? If not, on what factors ...
1
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1answer
41 views

Measuring mole fraction in lab using Raoult's law

I was reading in my textbook of chemistry on the vapour pressure in liquid compounds, and came across a doubt regarding vapour pressure. If I have two liquids, one is A and another is B, and if I know ...
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0answers
44 views

Effect of charge density on electrolysis of dilute sulphuric acid

I am told that if electrolysis of dilute sulfuric acid is performed under high charge density, then the following reaction takes place at anode instead of evolving oxygen: $$\ce{2 HSO4- -> H2S2O8 +...
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1answer
75 views

Why do azeotropes boil at constant temperature? [closed]

As given in the Wikipedia page, An azeotrope (/əˈziːəˌtroʊp/) or a constant boiling point mixture is a mixture of two or more liquids whose proportions cannot be altered or changed by simple ...
0
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1answer
24 views

Does PEO particle size decrease when dissolved in water?

I am looking to make metallic ink for inkjet printing and using PEO 1 wt% (MW ~600,000) as a binder. The print head I am hoping to use has a nozzle diameter of 80 microns. The metal powder dispersed ...
0
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2answers
120 views

Acidic nature of boric acid when its concentration high

Following statement was given for boric acid $(\ce{H3BO3}):$ At low concentrations $(\leq\pu{0.02 M})$ essentially $\ce{B(OH)3}$ and $\ce{B(OH)4-}$ are present, but at higher concentration the ...
0
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1answer
28 views

Seeing solubility in various cases

[![enter image description here][1]][1] Question is in the image 'match' each option having multiple answers. I have invested a considerable time over this but couldn't solve it. Anyone explaining how ...
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0answers
37 views

Two salts in mutual saturation, which one will precipitate first? [closed]

Let's say I have a satuated solution of two salts with a common ion e.g. KCl and KI, and they're at mutual saturation (let's say there are 75% by weight KCl/ 25% KI). If I slowly evaporate some water, ...
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1answer
24 views

Difference between homogeneous and heterogeneous mixture [closed]

When i mix two equal but large number of stones it is possible (though extremely unlikely) that stone a and stone b perfectly segregate themselves into two halves or that they are uniformly ...

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