An atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. An ion consisting of a single atom is an atomic or monatomic ion; if it consists of two or more atoms, it is a molecular or polyatomic ion.

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51 views

How many electrons does each shell hold?

why some times 2nd shell onward it can hold 8 electrons and other times it is like they can hold K2 L8 M18 N32? when do i have to use first method(K2 L8 M8 N8) and when to use second method (k2 L8 ...
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0answers
26 views

Aluminum foil in copper chloride solution

What is a physical change when Aluminium is put into Copper (II) Chloride. I know it is a chemical change but are there any physical changes
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0answers
41 views

Quantum Numbers and Ions

How do quantum numbers change for ions? A sample question: Give the set of four quantum numbers that could represent the electron lost to form the Rb ION from the Rb atom. The answer given is n=5; ...
2
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1answer
45 views

What is the reason for strong acids/bases dissociating in water?

I have read that the actual definition of a strong acid is one which will fully dissociate in water, so please do not turn the problem on its head when answering. It is also my understanding that ...
2
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2answers
65 views

Analogies of azide?

Azide is a fairly common ion, but why aren't there similar versions such as $P^-_3$ or $B_3^+$? Do they exist, is there something wrong with these ions as to make them more likely to just break apart ...
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1answer
38 views

How to remove nitrate from water sample?

Are there any simple methods to completely remove nitrate ions from few ml of impure water sample ? One method I am curious about is the following process : Add one or more reagents to water in ...
1
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0answers
20 views

Why does the molar conductivity decrease with increasing charge density?

This is a question in a problem sheet I have been set. Is it do do with the following equation: $\Lambda=\Lambda_0-a\sqrt c$? Surely charge density is proportional to concentration so therefore molar ...
3
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1answer
66 views

Can we picture metallic bonding as an equilibrium between electrons and cations?

Can we picture metallic bonding as an equilibrium between electrons and cations? Suppose: $$\ce{Al^3+ + 3e- <=> Al}$$
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1answer
33 views

What is more stable: a carbonate ion or a sulphate ion?

The sulphate ion has more number of resonance structures than the carbonate ion. Hence, it should be more stable than the carbonate ion. But my book says that the carbonate ion is stronger than the ...
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1answer
612 views

Can metals have a net negative charge

Normal metals like sodium or Calcium have a positive charge as $\ce{Na}^+$ or $\ce{Ca}^{2+}$. Transition metals have a loot of variable oxidation states. Yesterday I read about Iridium in Wikipedia ...
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1answer
26 views

Ionize Hydrogen and Oxygen Gas in Electrolytic Cell?

As is well known, water can be electrolyzed into oxygen and hydrogen gasses. However, all redox reactions can be run in reverse. If I were to electrolyze water in 2 closed containers (in order to trap ...
0
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1answer
20 views

How do you figure out the dissociation energy for ions?

Specifically $\ce{KF}$ into the $\ce{K+}$ and $\ce{F-}$ ions. I can find tables on the DE into atoms, but where would I go to find the DE between ions? I am also given that the bond length is ...
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0answers
48 views

Calculating the Molarity of an Ion?

I'm completely stuck on this one - I was doing an experiment in a lab and now I cannot find the molarity of an ion in a solution. I've looked everywhere on the web but after 2 hours of searching I ...
3
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1answer
24 views

When does a solute form ions?

If I have $\ce{HCl}$ and I put it in water, it will form ions. But, if I take $\ce{HCl}$ and put in benzene, it won't. How do you know that? If I had other substances, how would I know if it forms ...
9
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1answer
1k views

Is the atom the smallest particle, which takes part in chemical reactions?

According to modern atomic theory, the atom is the smallest particle which can take part in a chemical reaction. But during the formation of hydronium ion, $\ce{H+}$ ion reacts with $\ce{H2O}$ to form ...
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0answers
11 views

Separating ions in an aqueous solution [duplicate]

Let me describe a setup. You have a bucket full of water and add an appropriate amount of NaCl (common salt) in it. You wait for it to dissolve. Gradually NaCl will dissociate forming ions. Then you ...
2
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2answers
245 views

Why is the second reaction being neglected?

If we want to find the concentration of $\ce{H+}$ ions at equilibrium when a weak conjugate base such as $\ce{C2H3O2-}$ added to water, why do we take the conjugate base reaction for calculation i.e ...
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1answer
51 views

Why does the potential difference of a current drop, when silver nitrate is added to deionised water?

Semi-related to Why do some salt ions in solution conduct electricity better than others? After conducting more experiments, using deionised water as an analyte only, I found the potential difference ...
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2answers
106 views

Are Na and Cl ions from NaCl in water separate charged particles?

Suppose I pour some sodium chlorine into water. So, what happens is that NaCl(s) → Na+(aq) + Cl-(aq) meaning that the ionic bond between Na and Cl breaks up (correct this far?) Now, does this mean ...
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2answers
59 views

Why Ca 2+ and not Ca +2

I have been learning chemistry for a year or two but I still can't understand this. According to maths we should place the plus or minus sign in front of a number like -2. However, In chemistry we ...
1
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1answer
45 views

Does the speed of an ion affect the current that can flow through a solution?

Typically, when a cathode and anode are inserted into a solution that allows current to flow, the ions are moving with a certain kinetic energy. If the ions were to gain kinetic energy (through ...
2
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1answer
171 views

Why do some salt ions in solution conduct electricity better than others?

My experiment involves a potentiometric titration, and I have used $\ce{AgNO3}$ as a titrant and KCl/KI/deionised water only as an analyte. In the image below of my data, the potential difference as ...
3
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0answers
109 views

What is the total concentration (in mol dm−3) of ions in each of the following solutions, assuming complete dissociation

$0.750\ \mathrm{mol\ dm^{-3}}$ solution of $\ce{K2CO3}$ (I believe is $2.25\ \mathrm{mol\ dm^{-3}}$) $0.355\ \mathrm{mol\ dm^{-3}}$ solution of $\ce{AlCl3}$ (I believe is $1.42\ \mathrm{mol\ ...
5
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1answer
44 views

Ion-selective electrodes

Some ion-selective electrodes can be expensive (starting from $500). Is there any relatively inexpensive do-it-yourself alternatives that would still give very accurate results? How does one make an ...
2
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1answer
43 views

Iodine ion vs caesium ion size

An iodine ion is the larger of the two, but why if they have the same amount of electrons? Also, $\ce{Li}$ is larger than $\ce{Li+}$, don't more electrons mean larger radius?
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2answers
52 views

What is the OH in alcohol?

What is the $\ce{OH}$ functional group in alcohol (ethanol)? My teacher told me it isn't the same as the $\ce{OH-}$ ion or hydroxide. But it does donate one electron to the respective carbon chain and ...
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2answers
110 views

Why does Cobalt have different coordination numbers in its complexes with water and thiocyanate?

I'd like to know why does cobalt(II), $\ce{Co^2+}$, form $\ce{[Co(H2O)6]^2+}$ complex with water while it forms $\ce{[Co(SCN)4]^2-}$ with the thiocyanate? Why is there $\ce{6H2O}$ but only $\ce{4 ...
2
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1answer
57 views

Why should the redox reaction happen between the copper ions and iron atoms?

I know that when $Cu$$^+$$^2$ ions react to $Fe$ atoms, it becomes $Cu$ + $Fe$$^+$$^2$. My question is, why? Copper atoms normally have 29 electrons. These means that in the K-shell there are 2 ...
6
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2answers
234 views

Wade's rules for Zintl ions

How do you apply Wade's rules to Zintl polyhedral cluster anions ? For example, I believe $[\ce{Bi_3}]^{3-}$ is a triangle. My approach to justify would be: 5 electrons per each Bi atom 3 electrons ...
2
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1answer
47 views

How do I convert zwitterions to neutral form in Avogadro?

I'd like to be able to convert zwitterions to neutral form in Avogadro if possible. How do I do this?
2
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1answer
72 views

Why does the ionic product of water remain constant after addition of non-neutral solute?

In my textbook, it is given that the ionic product of water $K_w$ remains constant even when a non-neutral solute such as an acid is added to it. $$K_w=\ce{[H3+O][OH- ]}$$ When a strong acid is added ...
3
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2answers
127 views

Acidity of oxonium ion

How was the pKa value (-1.7) for the oxonium ion determined? Why does it correspond to the minimum pH value accessible in water? What reaction does it represent?
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1answer
44 views

Comparing Basic strengths of different species

Well I was doing questions on organic chemistry.I came across tonnes of questions where I was required to compare basic and acidic strengths. Comparing acidic strengths is fine - I remove an ...
8
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1answer
197 views

Negative ions and health: pseudo science or something more?

Over the last year or so I've heard from friends, who subscribe to holistic medicine, talk about negative ions, saying that they are good for your mental/physical health. Being the only one among them ...
2
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1answer
95 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. ...
0
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1answer
235 views

How is the dissolution of acetic acid that makes its aqueous solution a poor electrolyte?

I'm having a difficulty understanding the following quote from Wikipedia - Dissociation: Acetic acid is extremely soluble in water, but most of the compound dissolves into molecules, rendering it ...
0
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2answers
87 views

Hydrogen peroxide from water

Is it possible that $\ce{2 OH-}$ from water could react to form $\ce{H2O2}$? I mean most autoionization forms $\ce{H3O+}$ and $\ce{OH-}$. However I think it is possible that $\ce{H-}$ and $\ce{OH+}$ ...
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1answer
67 views

What kind of carbon ions exist?

I think there are $\ce{C^{4-}}$ and $\ce{C^{2-}}$ existing. How can we find the charge of ions in the elements? Should we look at the group or valence?
3
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2answers
78 views

Where does the Fe(III) ion go?

Iron(II)Sulphate solution is added to a test-tube. Following this, potassium manganate solution is added gradually to the test-tube as well. The observation seen is that the green solution turns pink ...
4
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1answer
165 views

Does Iron (III) Sulfate react with copper?

As my understanding, there should be an oxidation-reduction reaction: $$ \ce{2Fe^{3+} + Cu \rightarrow 2Fe^{2+} + Cu^{2+}} $$ However, I always see the process using $\ce{FeCl_3}$ to etch ...
0
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1answer
48 views

Why they have different flame colour?

At school, I learnt about the metal and their flame colour. Here's my observations. $\ce{K^+}$- Lavender $\ce{Ba^2+}$- Yellow-Green $\ce{Ca^2+}$- Yellow-Red $\ce{Li^+}$- Flame Red $\ce{Na^+}$- ...
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0answers
60 views

How to determine relative size of polyatomic ions?

How would you determine the size of a polyatomic ion? For example when determining which ion is bigger, NH2- or I-, what would you use to determine the size difference? I know that I- would be much ...
3
votes
1answer
96 views

Why is the hydride ion negative?

Recently, I saw a video about sodium hydride and it saw it was made up with $\ce{Na+}$ ions and $\ce{H-}$ ions. My problem is: aren't all hydrogen ions positive? And in what conditions can $\ce{H-}$ ...
0
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2answers
51 views

What is the bonding picture in Peroxomonosulfate?

In $\ce{SO5^{2-}}$, can somebody tell me which orbitals are used to form the pi bonds in this anion. Please tell the hybridization. And the lewis structure. Well I tried and the answers I got was sp3 ...
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1answer
31 views

number of ions present from moles

I have $0.0585$ moles of $\ce{Al^{3+}}$, and need to find the number of actual ions. I thought I just divided by $6.022\times 10^{23}$ but I get $9.7\times 10^{-26}$, and the book says it should be ...
5
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2answers
129 views

Should I use H3O+ or H+?

I learned the equation $$\ce{H2O + H+ -> H3O+}$$ And I know $\ce{H^+}$ and $\ce{H_3O+}$ are the same. But I am confused as to when can I use $\ce{H^+}$ and $\ce{H_3O+}$?
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1answer
82 views

How would you find the mass in grams, if you only know the number of particles of a portion of the formula? [closed]

If you were given a question like below: What is the mass in grams of a sample of $\ce{Fe2(SO4)3}$ that contains $3.59 \times 10^{23}$ sulfate ions, $\ce{SO4^{2−}}$ ? The molar mass of ...
2
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1answer
49 views

How thermochromism happen?

I learned that when $PbO$ is hot, it is orange. When $PbO$ is cold, it is yellow. I know this's called thermochromism. But how do that happen? Is it because the ions inside doing something?
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1answer
112 views

What is the difference between carboxylate ions and groups?

I would like to know the difference between carboxylate ions carboxyl groups? An example is is $\ce{COOH}$ and $\ce{COO}$.
3
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1answer
34 views

Why do strong acids dissociate (almost) fully on a molecular level?

In the Brønsted-Lowry theory, strong acids $\ce{HA}$ dissociate using water and react into hydronium ions and the conjugate bases $\ce{A-}$. However I never understood in the strong acids case what ...