Questions tagged [ions]
For questions about ions - atomic or molecular particles having a net electric charge. Do NOT use this tag just because your question involves ions but is not about the ions themselves (as in electrochemistry, etc.).
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Formation of trifluoride anion
I wanted to understand mechanism of the formation of $\ce{F3-}$ anion through the molecular orbital theory.
UPDATE - What I really want to know is that when $\ce{F3-}$ is formed from $\ce{F2-}$ and $\...
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Why does viscosity decrease when divalent cations are dissolved into aqueous solutions of sodium carboxymethylcellulose?
Sodium Carboxymethylcellulose (CMC/NaCMC/Aqualon) is a common product used in many instances for its unique properties, especially its ability to make solutions viscous. It is well known that the ...
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Volume of anion and comparison
Recently, I came across a book in which I was solving the exercises and found out that the solution to a question says that the fluoride ion, $\ce{F^-}$, is smaller in size than the hydride ion, $\ce{...
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Positive charge on a zwitter ion at pH=7?
I faced this question. But I am having some problems understanding the solution to this:
How can the negative charge on the peptide vanish on $\pu{pH = 7}$? Suppose, we have some $\ce{H+}$ donor on ...
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Calculate the molarity of Na+ ions in 20 mL of a .130 M solution of Na2Cr2O7?
The answer is $\pu{0.260 M}$, but I keep getting $\pu{0.0052 M}$ because I thought the right way to do it was by multiplying $\pu{0.130 M}$ by $\pu{0.02 L}$, then multiplying by $2$ moles of $\ce{Na+}$...
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Number of unpaired electron and total spin angular moment
IIT-JEE advanced 2013 has a question:
Give the correct order of the complex ions given below according to their spin-only magnetic moment:
A. $\ce{[FeF6]^{3-}}$
B. $\ce{[V(H2O)6]^{2+}}$
C. $\...
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2
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How exactly are ions in a Mass Spectrometer accelerated?
After a molecule is ionised, the ion is accelerated by an electric plate up to a certain kinetic energy by the attraction of the ion to the electric plate.
However, after the ion has passed the ...
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How do phase transfer catalysts bring anions to organic phase?
Many anions are quite stable in the aqueous phase, but not so much in organic solvents where its necessary to perform some reaction (usually nucleophilic substitutions). I have heard that crown ethers ...
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Is SO3 an ion or a molecule?
Earlier I thought that $\ce{SO3^{2-}}$ (sulfite) is an ion with -2 charge but today I read on internet $\ce{SO3}$ (sulfur trioxide) is a molecule with no charge. How can this be possible? Please ...
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How can I separate sodium ions from brine or molten NaCl?
Is possible to separate sodium ions from an aqueous solution of NaCl? If so, how do I go about it?
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What is the complete reaction for Cyanide ions reacting with Thiosulfate?
I was recently studying about the properties of Sodium Thiosulfate, where I came across the fact that $\ce{S2O3^2-}$ reacts with $\ce{CN-}$ ions to produce $\ce{SCN-}$ ions. This was quite useful in ...
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Ionic radius of Al[3+] compared to K[+], Ca[2+], S[2-], and Cl[-]
I came across this question:
Which of the following is bigger?
$$\ce{K+, Ca^2+, Al^3+, S^2-, Cl-}$$
Now, I know that the radius decreases as the period progresses to the right and increases as we go ...
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How does the HCl-KCl Buffer work?
I have just been studying the $\ce{HCl}$-$\ce{KCl}$ 'buffer', but there are still quite a few things I am uncertain about. I would appreciate any help in clearing up some questions I have.
What I ...
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If a bond dissociation energy is listed, does it refer to homolytic or heterolytic fission?
I am perfectly sure than heterolytic fission of a bond needs more energy than homolytic ones, since it requires opposite charge separation. When the bond dissociation energy is listed, which one are ...
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Can the hydride ion act as a ligand?
Hydride ion, as I know is a pretty powerful base, much stronger than hydroxide ion and cannot exist in an aqueous phase.
Can it act as a ligand in coordination compounds? Hydride ion has its ...
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How was it concluded that the H3O+ rather than H+ is the "acid" ion?
I suspect that initially, scientists believed that the acid ion was $\ce{H^+}$ since $\ce{H2}$ is released through electrolysis, right? But what experiment was done to change the standpoint to assume ...
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Why is the common magnesium ion Mg(II) and not Mg(I) when the second ionization energy is higher than the first ionization energy?
The first ionization energy for magnesium is given as $\pu{737.7 kJ/mol}$, and the second ionization energy is $\pu{1450.7 kJ/mol}$.
Given this information, doesn't it take $\pu{737.7 kJ/mol}$ to ...
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How does one classify aqueous solutions of ions as acidic, basic and neutral?
The following is a homework question:
Classify the aqueous solutions of the following ions as acidic, basic or neutral:
$\ce{C6H5NH3+, Cl- , Fe^3+ , Mg^2+ , HSO4- , NO3- , NH4+ , Al^3+...
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What do we call ions without basic and acidic properties
According to Brønsted theory,
Acids are substances (molecules and ions) donating $\ce{H+}$
Bases are substances (molecules and ions) receiving $\ce{H+}$
I've been trying to find a complete Brønsted-...
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Logical reasoning behind the formula for molar conductance of an electrolyte [closed]
I am studying some introductory material on electrochemistry. My book and all standard websites I've found define the molar conductance of an electrolyte as "conductivity of an electrolyte solution ...
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Why doesn't fluoride ion have highest nucleophilic power (nucleophilicity)?
As you can see from the image above,
'$\ce{R3C}$' anion has 1 lone pair
'$\ce{R2N}$' anion has 2 lone pairs
$\ce{RO}$ anion has 3 lone pairs
$\ce{F}$ anion has 4 lone pairs
According to VSEPR theory,...
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Can atoms other than hydrogen be reduced to a bare nucleus?
In acid-base theory, hydrogen is able to become the $\ce{H+}$ ion, or a bare proton. I'm curious if other, larger atoms can have their electrons stripped to the point of being only a nucleus. I know ...
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Cyanamide mesomeric contributors
Which form of the cyanamide ion is more stable?
As per the resonance rules, I find both of them equally stable as number of bonds is the same, more electronegative atom has negative charge and so on. ...
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Why is a cationic trialkylammonium functional group inductively withdrawing in nature?
The alkyl groups on the nitrogen ion should donate electrons (alkyl groups are electron donating in nature). So, irrespective of the nitrogen ion being a cation (which is an electrophile), the alkyl ...
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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 ...
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Hydration enthalpy of cations
Can someone provide reliable data on the solvation / hydration enthalpies of $\ce{Ti^{4+}}$ and $\ce{Cr^{3+}}$ ions, or explain which is more stable qualitatively? According to this article1
CFSE in $...
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How can nucleophilicity be estimated accurately?
Given the following: $\ce{CN-,OH-,SH-,I-}$. Determine the relative order of nucleophilicity in a protic solvent.
I know that, more the nucleophile is solvated by hydrogen bonding in a protic solvent,...
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Why can't some salts be used in the salt bridge of specific voltaic cells?
I had an exam question in reference to a galvanic cell with $\ce{Pb{(s)}}$ as the anode in $\ce{Pb^2+}$ solution and platinum cathode in a solution of $\ce{Fe^2+}$ and $\ce{Fe^3+}$:
Identify an ...
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How will Back-Bonding affect molecular geometry?
While going through a textbook, I came across the following line:
$\ce{R3C-}$ is pyramidal while $\ce{(CN)3C-}$ is planar due to lack of back bonding from the lone pair of carbon atom into the $\pi^...
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What makes certain zeolites better at ion exchange?
I would have thought that the bigger the pores in the zeolite, the more ions it can contain, and therefore the better the use of the zeolite for ion exchange.
However, zeolite A has small pores but ...
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Why is the inside of a cell both more acidic and more negative than its environment?
In a very simplistic way of thinking, an acidic solution has more positively charged $\ce{H+}$ ions present, whereas a basic solution has more negatively charged $\ce{OH-}$ ions present.
Can that be ...
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Different types of carbides [closed]
I am confused between different types of carbides such as
$\ce{CaC2}$, $\ce{Mg2C3}$, $\ce{Al4C3}$, $\ce{BaC2}$ or $\ce{BeC2}$.
And if they are different, why they are called carbides?
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When, how & why do atoms become stable. If they're always bonding, do pure elements even exist in the real world? What happens to unstable atoms? [closed]
I really can't get my head around the fact that an element has to always become stable by bonding.
Doesn't that mean that you can't actually find a pure element, and that it doesn't exist in it's true ...
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E-glass degradation in water
At the moment, a question puzzling me is why and how glass fibers degrade in water environment? As the degradation of the glass fibers occurs, its reduces the strength of them. As far as I know, the ...
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Why second ionisation energy greater than the first?
Why is the second ionisation energy for atoms with more than 1 electron in the outermost sublevel greater than that of the first, if you are removing an electron from the same sublevel ? Why is there ...
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What is the size of a Sulfate ion?
In terms of nanometers, what would the size be of an individual sulfate ion in solution?
Would its size exceed 0.5 nm? Enough to displace something that is held together with a gap of 0.35 nm?
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why is tertiary carbocation more stable than primary allylic carbocation?
According to general organic chemistry the order of stability is as follows:
aromaticity > resonance > hyperconjugation > inductive effect
Since primary allylic carbocation shows resonance as well ...
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In which solvent is AgBr least soluble?
The solute $\ce{AgBr}$ is least soluble in
A $\ce{H2O}$
B $1.0~\mathrm{M}\ \ce{FeBr3}$
C $1.0~\mathrm{M}\ \ce{CaBr2}$
D $1.0~\mathrm{M}\ \ce{AgNO3}$
I'm confused as to why the ...
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Penta-valent ion in water?
I would like to have a solution with a pentavalent positive ion. I need something that, preferably in water: $\ce{XY -> X^5+ + Y^5-}$. What can XY be?
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Enthalpy change of chromate-dichromate reaction
I am a uni study doing chemistry. I have taken a little bit in highschool before, but not in a while.
In a (nonassessed) practical, we have to predict how heating a chromate/dichromate solution:
$$\...
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Why is the overall charge of an ionic compound zero?
My textbook simply says:
Since an ionic compound consists of equal number of positive and negative ions, the overall charge of an ionic compound is zero.
But why is the number of positive and ...
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How do you calculate the heat of a reaction given a table of heat of formation values?
So I've been trying to answer this question, and as far as I've learned it's $\Delta H^0_{\mathrm f}$(products)-$\Delta H^0_{\mathrm f}$(reactants), multiplying each by number of moles and such.
...
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Why does the trimethylammonium cation have a larger -I effect than the ammonium cation?
Why does $\ce{N(CH_3)_3^+}$ have a larger $-I$ effect than $\ce{NH_3^+}$?
Since the methyl group is good at donating electrons it would stabilize the charge on nitrogen atom, decreasing its ...
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Finding the concentration of ferrous thiocyanate in calibration solutions
Concentration of $\ce{Fe(SCN)^{2+}}$ in calibration solutions
Recall that the concentration of $\ce{Fe(SCN)^{2+}}$ in the calibration solutions is essentially the concentration of the $\ce{SCN-}$ ...
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How is the tetrachloridocobaltate(II) anion stable if its crystal field stabilization energy comes to be positive?
I tried to calculate the ligand field stabilisation enthalpy of $\ce{[CoCl4]^2-}$ (as shown in the image) but found it to be positive. What could be the reason behind this? How is it stable with ...
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How do I convert this ion exchange capacity into water softening capacity?
I am researching for an extended experimental investigation into methods of water softening. One such method is the use of ion exchange resin. I have contacted the supplier of the resin for its ...
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Pattern to determine the maximum ionic charge for transition elements?
According to my textbook, main group elements follow a simple pattern when determining their maximum ionic charge. The maximum cationic charge is always equivalent to their main group number (group ...
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Comparing nucleophilicity
We have to compare the nucleophilicity of $\ce{OH-,NH2-,CH3CH2-}$ and $\ce{CH#C^{-}}$. I managed to find out that $\ce{CH3CH2-}>\ce{NH2-}>\ce{OH-}$ and that $\ce{CH3CH2-}>\ce{CH#C-}$. But I ...
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Why do substances ionise in water to turn into charged species? Wouldn't they prefer to stay as uncharged molecules?
Wouldn't this be more stable if they stayed as neutral molecules?
I've learnt that they will seek to reach the ratio of $[A]^a[B]^b/[C]^c$ that matches the $\ce{Ka}$ or $\ce{Kb}$ value.
But I do ...
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Could the difference between absorption time of Diclofenac Sodium and Diclofenac Potassium be related to the cation?
Diclofenac is a common non-steroidal anti-inflammatory drugs (NSAID) that comes in a variety of formulations. Two of the most common forms are diclofenac sodium and diclofenac potassium (the links ...
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