Questions tagged [aqueous-solution]

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

Filter by
Sorted by
Tagged with
4
votes
2answers
476 views

Do buffers only work for species of the opposite variety? (I.e. weak acids buffer strong bases and vice versa)

I have looked at several sources including Khan Academy, ChemCollective and the answer to a similar question: Can someone please explain buffers to me? However, it is not clear whether buffers can ...
4
votes
4answers
5k views

Why is zinc deposited on copper when boiling an aqueous zinc sulfate solution?

I did an experiment where I dissolved 30 grams of zinc sulfate in water and boiled it with strips of solid zinc metal and strips of copper metal and a layer of zinc was deposited on the copper. I ...
4
votes
1answer
316 views

Can Aquatabs be used to clean swimming pool water?

Can Aquatabs be used to prepare/chlorinate water for swimming? They are used to clean water for drinking so is it safe to assume that if used in proper quantity they can also clean water for ...
4
votes
2answers
203 views

Is water acidic enough for an redox reaction involving H+?

If you stored $\ce{Pb(NO3)2(aq)}$ in a $\ce{Cu(s)}$ container, would any reaction occur? Lead(II) ions will not react spontaneously with the copper solid as the $E^0_\mathrm{net}$ of the reaction ...
4
votes
1answer
1k views

Is the concentration of negative ions always equal to that of positive ions?

Is there any way in which a solution can have more negative charge than positive charge, or vice versa? For example, in the context of acid-base chemistry, is there any scenario in which $[\ce{H+}]\ne[...
4
votes
2answers
816 views

Basis for the hydrophobic effect?

I'm confused about why hydrophobic molecules, which do not have high polarity, would have a tendency to attract and cluster with themselves. It is easier to understand the hydrophilic as long as one ...
4
votes
1answer
4k views

What is the lethal dose ( LD50 ) of coffee?

Of course, there are many types of coffee, so I would like a range of lethal dose amounts for the average human, from the mildest of lattes to the most hardcore of espressos. Pure caffeine's lethal ...
4
votes
1answer
3k views

How to interpret the instruction of the dilution of hydrogen peroxide?

I am required to prepare $\pu{120cm3}$ of hydrogen peroxide to each of one of my students tomorrow. Some material is given to me on the method of preparing the solutions. Within the method of ...
4
votes
1answer
175 views

Could micrograms of polonium really change the viscosity of a whole teapot?

I was reading How radioactive poison became the assassin’s weapon of choice and it opens describing how The men eventually left, and Andrade cleared the table. As he poured the remaining tea away, ...
4
votes
1answer
329 views

Would the change in enthalpy (ΔH) for the dissolution of urea in water be positive or negative?

To test the properties of a fertilizer, $15.0\ \mathrm g$ of urea, $\ce{NH2CONH2(s)}$, is dissolved in $150\ \mathrm{mL}$ of water in a simple calorimeter. A temperature change from $20.6\ \mathrm{^\...
4
votes
1answer
274 views

Why does the conductivity of a LiOH solution decrease when boric acid is added?

If I start with pure water and add $\ce{LiOH}$ the conductivity of solution increases. However, if I then dissolve boric acid in the same solution the conductivity falls. I would have thought adding ...
4
votes
1answer
3k views

Why does hydrogen phosphate act as a base?

Let's look at question c: a) Write a balanced equation for the reaction. $$\ce{2 NaOH + H3PO4 -> Na2HPO4 + 2 H2O (l)}$$ b) When some crystals of $\ce{Na2HPO4}$ were dissolved in water, ...
4
votes
2answers
1k views

Diluting down solutions method

I'm designing an experiment and it involves testing various concentrations of solutions, and I will be testing 5 in total. I proposed to make up a stock solution, and distribute it evenly in 5 ...
4
votes
1answer
35k 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 ...
4
votes
2answers
669 views

If acyl chlorides are reacted with aqueous ammonia, will carboxylic acids also be formed?

As part of my A-level chemistry course, I have been taught that an acyl chloride will react violently with water to produce a carboxylic acid and hydrochloric acid. I have also been taught that an ...
4
votes
1answer
338 views

Finding equilibrium constant from solubility product constant

Given $$\ce{CuI(s) <=> Cu+(aq) + I-(aq)}\, ;\qquad K_\mathrm{sp} = 1.2 \cdot 10^{-12}$$ write a reasonable chemical reaction that describes the decomposition of $\ce{CuI2}$ in aqueous ...
4
votes
1answer
120 views

A problem in solubility of salts with multistep hydrolysis of an ion possible

Calculate the solubility of $\ce{MnS}$ in pure water, $K_\mathrm{sp}(\ce{MnS}) = \pu{2.5e-10}$. Assume hydrolysis of $\ce{S^2-}$ ion. $K_1$ and $K_2$ for $\ce{H2S}$ are $10^{-7}$ and $10^{-14}$, ...
4
votes
1answer
211 views

Could we reach a pH of 4.9 by blowing through straws?

According to Wikipedia's article on Breathing: The permanent gases in gas we exhale are 4% to 5% by volume more carbon dioxide and 4% to 5% by volume less oxygen than was inhaled. If I started ...
4
votes
2answers
2k views

Is lithium bicarbonate an aqueous solution of lithium carbonate?

This question is related to: Are Lithium bicarbonate and​ Magnesium bicarbonate both soluble in water? What type of chemical reaction is this? How can bromine water be called a solution? In the ...
4
votes
1answer
387 views

Relationship between the water ionization constant and ionic strength

I read in a textbook that the water ionization constant ($K_\mathrm{w}$) increases as the ionic strength of the solution increases and it confused me. If the ionic strength increased, then the ...
4
votes
1answer
137 views

Can cationic species form micelles?

Most of the books dive into formation of micelles by soaps. They go on talking about alkyl sulphate and carboxylates, but never do they mention anything about cations. My textbook says that at ...
4
votes
3answers
1k views

How can I keep homemade laundry detergent from disassociating?

We've been using this recipe to make laundry detergent. Works fine, but after a few days it disassociates into a clear bottom layer and a pink top layer. It's mildly annoying to have to re-stir it ...
4
votes
2answers
2k views

Does H2CO3 exist in solution?

When $\ce{CO2}$ reacts with water, it supposedly forms $\ce{H2CO3}$, which is the aqueous form of $\ce{CO2}$. But it is hard to isolate, but its $K_\mathrm{a}$ value is pretty low (on the order of $10^...
4
votes
1answer
2k 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. ...
4
votes
1answer
582 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 ...
4
votes
1answer
654 views

Does supersaturated caffeine polymerize?

I tried preparing a supersaturated solution of caffeine by mixing anhydrous caffeine powder with water in a thin Turkish tea glass and heating it up over a candle (desperate times...). This worked ...
4
votes
2answers
9k views

What is the process of turning ionic silver solution into colloidal silver solution?

I've looked at a number of different colloidal/ionic "silver solution generators." After my research I'm under a few impressions and if they're wrong please let me know. I also am wondering what ...
4
votes
1answer
481 views

Why do aqueous solutions always have to be electrically neutral?

I was reviewing some analytical chemistry and stumbled upon a section that explained the imperfection of using a salt bridge. It said that the using dissimilar ions is a problem because in, for ...
4
votes
1answer
165 views

What component(s) of instant coffee make it deliquescent?

If I put small, separate piles of instant black coffee powder, sugar, powdered creamer, and even something very ionic like table salt out in humid air and come back in a few days, only the instant ...
4
votes
1answer
87 views

What is the proper way to prepare a solution aiming to minimize errors?

I am a undergraduate student in chemistry, and my university is very weak in teaching solution preparation. I need to prepare a 10 mg / L methylene blue solution and now the way I do is, using an ...
4
votes
1answer
533 views

How can I calculate the molar conductivity of a solution with multiple solutes?

I'm running an experiment mixing 2 different solutions, $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{NaCl}$ with $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{KCl}$. I am measuring the conductivity of the total solution in $\...
4
votes
1answer
1k views

Why does pouring soda slowly and smoothly seem to keep more of the carbonation?

So, I caught myself gently pouring a can of soda into a cup of ice (making sure that there was room for air to move through so the stream of soda from the can to the cup was consistent and even) ...
4
votes
1answer
263 views

Balancing Redox Equations - Half Reactions

How do I balance this using the half-reaction method: $$\ce{Zn(s) + HCl(aq) -> Zn^{2+} (aq) + H_2 (g)}$$ I would first split it up in its ionic components: $\ce{Zn(s) + H^+ + Cl^- -> Zn^{2+} (...
4
votes
1answer
170 views

Boiling aluminum in high-alkalinity water

This question ultimately relates to brewing beer, but more specifically to water treatment before brewing. Though I can't get a water quality report, I suspect I have high levels of bicarbonate ...
4
votes
1answer
69 views

Boiling solutions with two salts

If you dissolve two different ionic compounds (that don't make a precipitate) in water and then boil the solution so all the water evaporates, the salts will re-crystallize. Is it possible that you ...
4
votes
2answers
1k views

Problems with precipitation of transition metal solution

I am trying to make a solution of "trace elements"--primarily transition metals-- for use in biological media; bacteria require elements like Cobalt, Molybdenum, iron, etc. in trace amounts. I am not ...
4
votes
1answer
16k 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 ...
4
votes
1answer
2k views

How is hydration free energy of a solute measured experimentally?

I am reading a paper (Shirts, M. R.; and Pitera, J. W. and Swope, W. C. and Pande, V. S. J. Chem. Phys. 2003, 119, 5740-5761). Near the beginning of the paper (page 5745), the authors state: ...
4
votes
1answer
283 views

How many protons does phenolphthalein lose in basic solutions?

So, I've looked it up and Wikipedia claims that two protons are released by Phenolphthalein when pH is over 8.2, but I've seen other sources that claim only one proton is lost. So, is it really just ...
4
votes
1answer
998 views

Temperature change and gas evolution for vinegar and baking soda experiment

This is sort of 2 questions in 1, but I think they are related. Could someone please explain why this endothermic reaction doesn't further decrease the temperature when the amount of baking soda is ...
4
votes
1answer
362 views

Counterions in adsorption of ions

When an ion is adsorbed from an aqueous solution onto a solid, what happens to its counterion? Obviously, the solution does not become charged - does this mean that it too is adsorbed? (Example: $ \...
4
votes
1answer
2k 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{...
4
votes
1answer
180 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, ...
4
votes
1answer
132 views

Best x-ray dopant?

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 $\mathrm{12\ wt\%}$ sodium iodide ($\...
4
votes
1answer
243 views

How does the composition of ice differ from that of water in a partly frozen solution?

Take any solution, then start freezing it at sufficiently low temperature. Soon a small amount of ice forms. I'd like to know how the composition of dissolved salts and gases in the bit of ice differs ...
4
votes
1answer
145 views

Why is Iron very rare in seawater compared to many other elements?

I don't know the associated technical words to research this question. There was high presence of Iron in the oceans in anoxic precambrian times, and today copper is 5 times more abundant in the ...
4
votes
1answer
79 views

Colloids and Ions

Suppose I have this reaction: $$\ce{3NaOH(aq) + FeCl3(aq) → 3NaCl(aq) + Fe(OH)3}$$ My questions: $\ce{Fe(OH)3}$ doesn't have the (aq) suffix because it isn't separated in water as opposed to $\ce{...
4
votes
1answer
323 views

How would an increase in the concentration of a sucrose solution affect the rate of its acidic hydrolysis?

Regarding the acidic hydrolysis of sucrose $$\ce{\underset{sucrose}{C12H22O11} + H2O + \underset{catalyst}{H+} -> \underset{glucose}{C6H12O6} + \underset{fructose}{C6H12O6} + H+},$$ I think ...
4
votes
1answer
376 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
votes
1answer
340 views

Does carbonated water change over the course of several days, or was my container leaky?

I have a Klean Kanteen flip-top growler, allegedly leakproof at up to 35psi of pressure, that I filled with some freshly-carbonated water 4 days ago — just to see how long it would last. I used a Soda ...