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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Why is it that every snowflake is unique?

It's pretty hard to believe in around 4.5 billion years of this planet's existence, no snowflake pattern was repeated, and that's not including potential earth-like planets. Is there a proof to the ...
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18 votes
3 answers
2k views

How do Precipitation Reactions behave in the Absence of Gravity?

How do precipitation reactions behave in the absence of gravity, say on the International Space Station (ISS)? I have seen water taking the shape of a sphere and not that of the container in space due ...
Vishnu's user avatar
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13 votes
3 answers
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Why exactly does precipitation occur?

In a solution, we have ions floating around but when we have a precipitate, they're arranged as they would be in a solid. This conversion should cause a decrement in the entropy of the system and ...
Shikhar_Mohan's user avatar
12 votes
1 answer
230 views

In the wet medium of an ocean, how does a hard shell form?

In general, if you were to try make something hard in a liquid medium (especially water) it is quite difficult to make the material solid. Things such as mollusks though, have no problem generating ...
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11 votes
1 answer
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Reaction of barium peroxide forming barium carbonate

I stumbled across this reaction: $$\ce{BaO2 + H2CO3 -> BaCO3 + H2O2}$$ This reaction seems quite similar to the variant with sulfuric acid $$\ce{BaO2 + H2SO4 -> BaSO4 + H2O2}$$ which is well ...
G. Ünther's user avatar
10 votes
3 answers
4k views

Experimental calculation of solubility product constant

In order to calculate the $K_\mathrm{sp}$ of lead(II) iodide, I mixed $\pu{6.0 mL}$ of $\pu{0.01 M}$ $\ce{Pb(NO3)2}$, $\pu{6.0 mL}$ of $\pu{0.02 M}$ $\ce{KI}$, and $\pu{8.0 mL}$ of water, and a ...
Henry's user avatar
  • 219
9 votes
7 answers
31k views

What is the simplest way to create a precipitation reaction at home?

What is the easiest way to create a precipitation reaction at home, preferably with easily retrievable chemicals? I need this because I'm making a video for my film education.
felix's user avatar
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9 votes
4 answers
144k views

Reaction of silver nitrate and hydrochloric acid

Consider the reaction of $\ce{AgNO3}$ and $\ce{HCl}$. I read that silver chloride would be formed. But $\ce{H} > \ce{Ag}$ in reactivity, then how could $\ce{Ag}$ displace $\ce{H}$ from $\ce{HCl}$ ? ...
RandomStudent's user avatar
8 votes
3 answers
1k views

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 ...
uhoh's user avatar
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8 votes
2 answers
2k views

Why do carbonates, oxides, and pure metals precipitate before metal sulfides?

Water tends to leach metals near the surface and deposit them deeper through precipitation in two layers. The upper layer is usually made of metal carbonates, oxides, and occasionally pure or native ...
Dale's user avatar
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8 votes
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Saturation of multiple solutes

Can a liquid which is saturated with a single solute, dissolve a different solute, or is saturation a universal thing? I ask because I’ve seen that different solutes have different points (amounts) at ...
Yurelle's user avatar
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8 votes
1 answer
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What is the chemical composition of Turnbull's blue?

I was studying qualitative analysis from this book and I found some tests for testing the presence of the cation $\ce{Fe^{++}}$. There was a test in which we add $\ce{K4[Fe(CN)6]}$ solution to a ...
najayaz's user avatar
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8 votes
3 answers
26k views

How does boiling water affect its hardness?

Does boiling water reduce its hardness, or on the contrary, increase it? It seems there are ambivalent phenomena at play here: boiling will evaporate pure water, thus increasing the concentration of ...
sc28's user avatar
  • 181
8 votes
0 answers
224 views

Mysterious violet-purple compound in "Gerber Method" & "Banana oil synthesis"

During the determination of fat in milk (Gerber method), in a milk butyrometer are mixed milk + $\ce{H2SO4}$ 90% w/w + isoamyl alcohol (isopentyl alcohol) and heating. The acidic mixture separates ...
Stefano's user avatar
  • 109
8 votes
0 answers
291 views

DIY hand sanitiser solution forms spongy substance

I am trying to make my own hand sanitiser since it’s sold out everywhere. The formula I use is 1 part aloe vera gel in 2 parts 100% isopropyl alcohol. The problem is when mixing the two, the solution ...
Fried Rice's user avatar
7 votes
2 answers
23k views

What reactions occur when mixing copper sulfate and sodium hydroxide?

I tried reacting copper sulfate with sodium hydroxide to get copper hydroxide, which should precipitate, according to the following equation: $$\ce{2NaOH + CuSO4 -> Cu(OH)2(s) + Na2SO4}$$ I ...
QuarterShotofEspresso's user avatar
7 votes
3 answers
18k views

Why does silver sulfate not precipitate in this double displacement reaction?

Aqueous silver nitrate is mixed with aqueous sodium sulfate. We were asked to perform this reaction in lab in my chemistry class, and we did not observe a precipitant being formed. However, the ...
vasilescur's user avatar
7 votes
3 answers
3k views

How much calcium hydroxide will precipitate after addition of sodium hydroxide into saturated calcium hydroxide solution?

Below was question 34 in the USNCO 2017 exam: If $\pu{0.10 mol}$ of solid $\ce{NaOH}$ is added to $\pu{1.00 L}$ of a saturated solution of $\ce{Ca(OH)2}$ $(K_\mathrm{sp} = \pu{8.0 \times 10^-6})$, ...
George Tian's user avatar
  • 1,361
6 votes
4 answers
23k views

When our hard water is boiled, it leaves a blue-green residue in our kettle.

The inside of our kettle is lined in a blue-green deposit. Our water is very hard, but what minerals could cause the coloration?
katmanduu's user avatar
6 votes
3 answers
1k views

How can I make a black precipitate without a sulfide?

I'm supposed to make a black precipitate using only the following chemicals: copper sulfate(II), lead nitrate, acetic acid, barium chloride, sodium hydroxide, copper(II) carbonate, methanol, potassium ...
michelehipp's user avatar
6 votes
1 answer
614 views

What chemical reaction can cause this blue-ish deposit?

Recently I noticed that some of our glasses and cutlery had developed a blue-ish deposit as you can see for the two sets of spoons below. For each set the spoon on the left has the blue-ish deposit ...
Michiel's user avatar
  • 6,700
6 votes
2 answers
1k views

How to find the mass of dissolved AgCl when placed in a solution of NaCl?

I think the following problem in my textbook is malformed: Solid $\ce{AgCl}$ is placed in $1\,\mathrm{L}$ of $0.55\,\mathrm{M}$ $\ce{NaCl}$. Find the mass of $\ce{AgCl}$ which dissolves. I know ...
math_lover's user avatar
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6 votes
1 answer
175 views

Determine the concentration of hydrogen cations to prevent precipitation of monocalcium phosphate?

Determine the $\ce{[H+]}$ needed to just prevent precipitation by $\ce{H2PO4-}$ in a $\pu{0.25 M}$ $\ce{H3PO4}$ solution that has $\ce{[Ca^2+]} = \pu{0.15 M}$. The $K_\mathrm{a1}$ of $\ce{H3PO4}$ is ...
carbenoid's user avatar
  • 2,032
5 votes
2 answers
251 views

Finding sulfate contamination in crystallized silver nitrate

What is the best way to check for a small amount of sulfate contamination (if any) in silver nitrate? Usually, I would use dilute barium chloride to precipitate out the resulting insoluble white ...
Qst's user avatar
  • 53
5 votes
3 answers
2k views

CaSO4 precipitate in mixture of Na2SO4 and CaCl2 solutions

I have been stuck on a chemistry problem for a long time now and if anyone here can help me I would be eternally grateful. 40. Du tillsätter $\pu{100 ml}$ $\pu{0,01 M}$ $\ce{Na2SO4}$-lösning i $\pu{...
Dumbstudent's user avatar
5 votes
1 answer
2k views

Mathematical explanation of blank titration in Mohr method for argentometry

In my book it is written that in order to minimize systematic error in Mohr method for argentometry it is a common procedure to conduct a blank titration with $ \mathrm{Ag^+} $ against a $\mathrm{CrO_{...
Mirko's user avatar
  • 197
5 votes
2 answers
2k views

Aluminium sulphate solubility as function of the pH

earlier I asked about how to know the aluminium sulfate solubility as function of the ph (see the previous question here). I found this diagram on the page 57 of Rubin, A. J., & Hayden, P. L. (...
Daniel Valencia C.'s user avatar
5 votes
1 answer
1k views

Constructing an equation for the precipitation of a salt

I was asked to write a balanced equation, as well as the net ionic equation, for the formation of $\ce{CaCO3}$ by precipitation. The equations should also include state symbols. Unfortunately, I am ...
Jordan's user avatar
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5 votes
1 answer
429 views

Is chromate a suitable indicator for the titration of Ag⁺ with Cl⁻?

To titrate $\ce{Cl-}$ with $\ce{Ag+}$ we use chromate $\ce{CrO4^2-}$ as an indicator. The titration reaction is: $$\ce{Ag+ + Cl- <=> AgCl}\tag{R1}$$ $$K_1 = \frac{1}{K_\mathrm{sp}(\ce{AgCl})} =...
user208973's user avatar
5 votes
2 answers
750 views

What's the reddish powder that oozes out of a black rock?

As an artist, some of the work I do involves the use of seashells, sea rocks/stones, etc. I picked up a black rock from shore at one of the beaches here in Florida and it looked somewhat clumpy with ...
Rob's user avatar
  • 51
4 votes
4 answers
31k views

Difference between precipitation and crystallisation

What is the main difference between precipitation and crystallization. Is precipitation a chemical change and crystallization a physical change. How can we say that the resulting solute is precipitate ...
Ayesha Ahmed's user avatar
4 votes
2 answers
4k views

Method and Tips for Inorganic Qualitative Analysis

In a few weeks time, I will be doing an inorganic qualitative analysis test which is very pressed for time (a majority of people don't finish). The form of the test is most likely going to be that ...
Nanoputian's user avatar
  • 7,372
4 votes
1 answer
356 views

Why is only the carbonate anion used to precipitate Barium?

Q: Why is the $\ce{CO3^2-}$ anion used to precipitate Barium from $\ce{BaBr2}$ and not another anion, such as $\ce{PO4^3-}$, or $\ce{SO4^2-}$? I am studying high school Chemistry, and the current ...
Archie 's user avatar
4 votes
1 answer
4k views

How to remove sulfuric acid from sample

I have problem with my experiment. My experiment is acid hydrolysis of ethyl benzoate. The acid that I used is sulfuric acid. My problem is when I get the precipitate (impure benzoic acid) I have to ...
Ladybee's user avatar
  • 41
4 votes
1 answer
8k views

Do all double displacement reactions lead to precipitates?

I know that most of the double displacement reactions form some kind of precipitates as their products. But do all of the double displacement reactions form precipitates? I have searched on this site ...
Hardik's user avatar
  • 176
4 votes
1 answer
230 views

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 ...
uhoh's user avatar
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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 ...
Karsten's user avatar
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4 votes
1 answer
280 views

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 ...
Dirk Bruere's user avatar
  • 1,590
4 votes
1 answer
455 views

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 ...
Hallucineon's user avatar
4 votes
2 answers
2k 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 ...
Ryan's user avatar
  • 1,167
4 votes
1 answer
942 views

Which calcium salt is good enough to make calcium benzoate?

This question is inspired from the following questions: Reaction of citric acid and calcium chloride Precipitation of citric acid by CaCl2 and Ca(OH)2? The answer to the 1st question says that ...
Nilay Ghosh's user avatar
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4 votes
1 answer
4k views

How to determine which salt will precipitate from a solution containing multiple ions?

I have a solution containing $0.2\:\mathrm{mol}$ of $\ce{Br^-}$ ions and $\ce{SO_4^2-}$ ions each. Now if I add excess $\ce{AgNO3}$ in this solution, what will precipitate? $\ce{Ag2SO4}$ or $\ce{...
pikachu's user avatar
  • 801
4 votes
3 answers
165 views

Does brewing tea with hard water reduce the amount of bioavailable fluorine?

I read that brewed tea contains a relatively large concentration of Fluorine. Fluorine can have negative health effects such as Skeletal Fluorosis. EDIT: I understand some Fluorine is necessary and ...
ericnutsch's user avatar
4 votes
1 answer
658 views

Gravimetric analysis of barium or sulfate

Which is a better way to obtain barium sulfate precipitate for gravimetric analysis: by adding $\ce{Ba^2+}$ ions to sulfate ion solution, or the other way round? I think it is better to precipitate ...
Uros's user avatar
  • 286
4 votes
1 answer
189 views

Measurement of Water Clarity

Turbidity is essentially the clarity of water. Turbidity can be measured in many ways such as a turbidimeter, secci disk or a turbidity tube (which incorporates a secci disk at the bottom). If you had ...
Bob Dylan's user avatar
  • 101
3 votes
2 answers
1k 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 ...
PurpleMoneys89's user avatar
3 votes
3 answers
960 views

Obtain precipitated iron?

Is it possible to obtain pure, precipitated iron with no oxidation by some chemical process? Alternatively is it possible to electrically purify iron using an anode and cathode?
Shaka Boom's user avatar
  • 2,324
3 votes
2 answers
450 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 $\ce{NaCl}$, $0.04M$, $...
Johnny Bueti's user avatar
3 votes
2 answers
23k views

Reaction of citric acid and calcium chloride

I was planning to extract citric acid from lemon juice by reacting the lemon juice with calcium chloride hoping it would react to form calcium citrate and precipitate according to the reaction $$\ce{...
Markovian8261's user avatar
3 votes
2 answers
10k views

Why are transition metal hydroxides insoluble?

From what I understand, adding $\ce{NaOH}$ to a solution containing transition metal ions gives transition metal hydroxide precipitates. Why is $\ce{NaOH}$ soluble but transition metal hydroxides ...
Meep's user avatar
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