Questions tagged [precipitation]

For questions related to the chemical reactions and processes that result in a chemical reaching its solid phase.

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3 answers
115 views

What is the precipitation reaction?

I asked my teacher if the reaction $$\ce{(NH4)2CO3 (aq) + MgBr2 (aq) <=> MgCO3 (s) + 2(NH4)Br (aq)}$$ can be considered a displacement reaction. She answered that it was a precipitation reaction ...
1 vote
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Would a container made of sugar eventually dissolve if filled with a sugar-saturated solution of water?

Suppose you had a bottle made of sugar glass, and filled it with water that was already saturated with sugar. I know that with a fully saturated solution of sugar in water, no additional sugar can ...
2 votes
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Why is it recommended to not store commercial sodium silicate solutions in direct sunlight, what are the effects of doing so and can it be modelled?

I regularly purchase aqueous sodium silicate solutions from commercial providers for my studies and note that a storage recommendation for all different grades (i.e. differing $\ce{SiO2 / Na2O}$ ...
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1 answer
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Why are iodine precipitates yellow? [closed]

Why do iodine precipitates appear yellow? Learning about precipitates I noticed that compounds like Lead Iodide and Silver Iodide are yellow.
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Is hard tap water useful for "salting out" a liquid organic solute?

We use methylene iodide ("MI", CH2I2) as a heavy liquid for sink-swim mineral separation. We use acetone to wash the MI off of the minerals and glassware after we're done. MI is pretty ...
1 vote
1 answer
124 views

How do I find the minimum amount needed for precipitation?

I want to calculate the minimum amount of solid barium nitrate (g) needed to be added to $\pu{50mL \text{of} 0.05mol/L}$ sodium hydroxide in order to cause precipitation. My attempt: $$\ce{2NaOH(aq) + ...
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1 vote
1 answer
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Why does CaSO4 break up when adding HCl but not BaSO4?

I observed in a solution with CaSO4 that the white precipitate dissolved when I added concentrated hydro chloric acid (37%). I assume CaSO4 had a divorce and Ca decided to hook up with two Cl- ions, ...
3 votes
2 answers
374 views

Magnesium vs calcium vs barium ions from these 3 tests

How do I pick up the difference between barium, calcium, and magnesium ions? I had to do a quantitative analysis practical exam: I was given an aqueous solution of a salt, and when adding separately ...
3 votes
2 answers
298 views

Doubt on the process to determine the amount of precipitate of a salt, product of a reaction between two solutions

I am attempting to determine whether there is going to be the formation of a $\ce{AgCl}$ salt precipitate if the following two solutions were to be added together: $50mL$ of $\ce{NaCl}$, $0.04M$, $...
1 vote
1 answer
126 views

Why and how do aqueous silica systems precipitate and can its occurrence be mitigated by quantifying its speciation correctly?

Background/Context: For context, I have been doing a lot of work on experimental systems in geopolymer chemistry lately with a focus on "activator" solutions which are essentially mixtures ...
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How does temperature affect ionic Ca in milk

I’m doing an investigation on the effects of temperature on ionic calcium content in milk through a classic EDTA titration method and have a few questions: — what is the scientific theory behind the ...
2 votes
0 answers
110 views

Will ethanol precipitate lipid-saccharide compounds?

I have a cell-free solution of culture broth. It contains a wide range of compounds ranging from salts (marine broth), lipids, and proteins to polysaccharides. My goal is to extract all type of ...
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1 answer
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Does nickel precipetate gold and copper?

I dissolved some CPU s and RAM s in aqua regia the day after I found a green solution with black powder in the bottom. So what just happened is it nickel or tin from solder?
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1 vote
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How to theoretically determine if a hydrate of a salt precipitates out of solution

In a solid-liquid extraction simulation process, there are multiple salts that precipitate in the solution. But how do I determine if these salts are hydrates or not? To give an example: $$\ce{Ca3(PO4)...
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1 answer
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Why urea crystallizes in aqua regia? [closed]

Recently I stripped gold from old cpu's with ferrous chloride after that I rinsed the cpu's and dissolved them in the aqua regia to get the gold inside when all done, I added urea solution to the ...
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-2 votes
2 answers
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Isolating potassium chloride from sodium chloride and potassium hydroxide

Assume that you have an aqueous solution of sodium chloride and potassium hydroxide. Is it possible to isolate potassium chloride from this? I'm thinking about the following: Na+(aq) + Cl-(aq) + K+(aq)...
0 votes
1 answer
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What happens when we react a sulfate salt solution with barium chloride and the formed precipitate with conc. hydrochloric acid?

When I performed this experiment in my school, I could not observe any sort of remarkable change (I must have performed it incorrectly or something). I wanted to know what should have been the correct ...
1 vote
1 answer
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How do I separate an Indium-Gallium alloy into Indium and Gallium?

I've recently learned more about Indium and Gallium, and I find them quite interesting, especially how an alloy can be manually made simply by rubbing them together. I'm curious though, is there a ...
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2 answers
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Precipitation of equimolar amounts of chloride and bromide [duplicate]

I was just wondering about the following situation; if we had a solution containing 0.1M bromide and 0.1M chloride ions, and treated it with excess silver nitrate, what would happen and would ...
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1 vote
0 answers
44 views

Converting dissolved chromates to solids for disposal

I have 4 liters of electrolysis waste that was used to process stainless steel cathodes. About half of it was oxalic acid based and the other half was sodium bicarbonate based (currently stored ...
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0 answers
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Does Sodium Precipitate with anything to find the level when titrating?

I am trying to find sodium in animal feeds. I already have a procedure to find chloride by using Mercuric Nitrate to form Mercuric Chloride using a titration method but am having a difficult time ...
0 votes
1 answer
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How to determine whether a solid has dissolved or no reaction occurred? [closed]

From this link: https://chemhaven.org/che111/lab/Lab_9_Unknown_Anion_F21.pdf When dissolving a solid or precipitate, only a portion is dissolved, thus leaving some behind, and fooling a student into ...
2 votes
2 answers
124 views

Are there any cold temperature reactions in liquid where ice forms as a precipitate?

The title asks the entire question, but I'll elaborate: Precipitates form in aqueous reactions when some product is insoluble in water. Is there a reaction in some other solvent where solid water ...
-3 votes
1 answer
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The meaning of USFDA (in cosmetics) [closed]

The full meaning of USFDA base on the definition of cosmetic meaning and production
-2 votes
1 answer
761 views

Is BaSO4 (barium sulphate) soluble or insoluble in diluted HNO3 (nitric acid) and diluted HCl (hydrochloric acid)? [closed]

Here's the original question , I was asked in an exam : Edit : the question in the picture is a single correct multiple choice question I have concluded the the reaction of Barium chloride and Sodium ...
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1 answer
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Displacement of salts due to higher solubility

I was wondering why mixtures of salts in the same solution precipitate excactly in order of their solubilities. Imagine a solution with NaCl, NaBr, NaI in equal moles. If AgNO₃ solution is now added ...
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1 vote
1 answer
154 views

How to predict colour of precipitate? [duplicate]

I am currently preparing for Junior science competitions and I am coming across many questions where colour of precipitate plays important role... Like When compound $\ce{Hg2(NO3)2}$ reacts with $\ce{...
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4 votes
1 answer
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Why use "molecular equation" to refer to a chemical equation describing a precipitation reaction?

When we describe a precipitation reaction using a chemical equation, we have the choice of either writing the net ionic equation (i.e. leaving out spectator ions) or writing the respective ionic ...
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1 vote
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Why does the reaction between copper(II) ion and iodide ion proceed even though the E_cell of the set up is negative?

(iii) Another example of a reaction that does not agree with the theoretical prediction is the reaction between $\mathrm{Cu}^{2+}$ and $\mathrm{I}^{-}$ according to the equation below. $$ 2 \mathrm{Cu}...
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How do I get calcium citrate to precipitate in experiment on extraction of citric acid from juice?

I was planning to extract citric acid from mango juice by first using Aspergillus niger fungus by fermentation to convert the mango juice to citric acid, then extracting by first adding sodium ...
-1 votes
2 answers
38 views

Ambiguity in the direction of dissolution equilibrium

The following reaction is usually carried out to test for the carbonate anion in an inorganic salt; $$\ce{CO3^2- +BaCl2/CaCl2 -> BaCO3/CaCO3(s) + 2 Cl-}$$ The resulting carbonate is stated to be an ...
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Identification of salts observed in steam vaporiser

Recently I observed some precipitated salts in steam vaporizer after completion of vaporization. I am guessing that some of the white particles may be calcium carbonate ($\ce {CaCO3}$) formed from ...
2 votes
1 answer
83 views

Iron-II to iron-III change in complex formation

We have an iron dust sample, which is treated with hydrogen chloride in aqueous solution. The solution enters in a reaction with a sodium hydroxide powder, from which we obtain a precipitate. Could we ...
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Why is the Ag+ concentration in a beaker fixed in the reaction between excess AgCl (s) and KI (aq) from the start? [duplicate]

This arises as a sub-question for the following question: Calculate the concentration of I- in a solution obtained by mixing 0.10 M KI with an excess of AgCl(s). I tried to look at How does addition ...
0 votes
0 answers
164 views

Adding aluminum sulfate to neutralize an aqueous solution of sodium silicate with pH of 12.6

How much aluminum sulfate do I need to add to an aqueous solution of sodium silicate to neutralize the solution (pH from 12.6 to 7)? For a water treatment school project, we remove sodium silicate ...
1 vote
0 answers
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Why is hydrated barium peroxide used in the preparation of hydrogen peroxide?

I read about the laboratory method of producing hydrogen peroxide. The chemical reaction in question is: $$\text{BaO}_2.8\text{H}_2\text{O} + \text{H}_2\text{SO}_4 \rightarrow \text{BaSO}_4+\text{H}_2\...
1 vote
1 answer
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Si(OH)4 vs. H4SiO4 vs. SiO2.2H2O

Can someone please explain to me what is the differences between $\ce{Si(OH)4}$, $\ce{H4SiO4}$, and $\ce{SiO2.2H2O}$? I am currently studying sandstone acidizing geochemical models and this question ...
2 votes
0 answers
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Can I extract solid sugar from any fruit juice at home?

The goal here is to isolate the sugar from all other compounds in the juice. In this case, I'm using apple juice and grape juice. The sugar does not need to be edible, as it is being used to make r-...
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1 answer
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Precipitation of a lead(II) sulfate

Lead (II) sulfate precipitate can be dissolved if: a) We add an acid b) We add EDTA c) None of the above is true. I think EDTA is a ligand, and if you want to dissolve the sulfate, then Pb sticks ...
4 votes
2 answers
556 views

Why do reusable heat packs have a limited time frame before the reaction becomes irreversible?

I have two "rechargeable" heat packs which from my understanding operate on the phase change $$ CH_3COONa_{(aq)} \rightleftharpoons CH_3COONa_{(s)} + \Delta H.$$ Triggering the ...
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8 votes
3 answers
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Can precipitation occur in states of matter other than liquids?

This answer to Are precipitation and crystallization both analogous between chemistry and meteorology? discusses the history and use of the term "precipitation" in chemistry. From what I ...
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4 votes
1 answer
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Are precipitation and crystallization both analogous between Chemistry and Meteorology?

A comment under the Space SE question Is there really precipitation on Mars? Does frost count? brings up the use of the term "precipitation" in chemistry and we wonder if precipitation in ...
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1 vote
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Reaction of Glucose + NaOH + PVP

I'm trying to synthesize of silver particles by using glucose as reducing agent, PVP as dispersant, and NaOH as pH control. Before adding silver nitrate solution, I've produced a solution which is ...
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A problem regarding solubility and concentration

A solution is $\pu{0.10 M}$ $\ce{Ba(NO3)2}$ and $\pu{0.10 M}$ $\ce{Sr(NO3)2}$. If solid $\ce{Na2CrO4}$ is added to the solution, what is the $\ce{[Ba+]}$ when $\ce{SrCrO4}$ begins to precipitate? $\...
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4 votes
1 answer
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Co-precipitation particle size

If we are creating a precipitate of (say) Barium Sulfate from a solution of Barium Chloride mixed with Sodium Sulfate, what determines the particle size? I assume one of the factors will be ...
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Solubility Product, and it's relation to solubility

In order to remove temporary hardness of water, it is boiled. On boiling, while Ca(HCO3)2 gives CaCo3(ppt.) , Mg(HCO3)2 gives Mg(OH)2(ppt.). According to my book precipitation of Mg(OH)2 occurs due to ...
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4 votes
1 answer
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Why is the test for sodium as dihydrogen antimonate so specific?

I have been attending lectures of salt analysis in my college. We are at group 6 cations or also known as group zero cations, namely $\ce{NH4^+}$, $\ce{K^+}$, $\ce{Na^+}$, $\ce{Mg^2+}$. The lecturer ...
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Material properties differing between vacuum or pressure filtration

During vacuum filtration of a very fine suspension, all solids that need to be removed are, but there is minimal solids loss. If the same material is pressure filtered (1-2 bar), desired solids ...
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2 answers
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Seperating out iron from ferrous sulfate

I don't need to necessarily seperate pure iron, but from a ferrous sulfate solution, I am trying to form a precipitate with iron. By getting a precipitation of an iron compound, I can find out the ...
0 votes
4 answers
436 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 ...