Questions tagged [chemical-formula]
For questions related to molecular formula, empirical formula, formula unit, representing the chemical proportions of atoms that constitute a particular chemical compound, molecule, ion, complex, crystal, etc. using chemical element symbols, numbers, and other symbols. NOT related to 'notation', 'composition', 'structure' or 'nomenclature'.
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Where is the negative charge localized in tetrazolate ion?
I am seeing images of tetrazolate ion where the negative charge is placed at different locations:
On the nitrogen atom
Inside the tetrazole ring
or
On the carbon atom
Is there any electronic ...
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What does ‘S/A’ mean in SMARTS pattern when using Chemicalize to draw the chemical structure?
I am still new to the SMARTS annotation. I am wondering what does S/A’ mean on the bond labeling drawn with Chemicalize using SMARTS [!#1]c1n[cH]nc([!#1])c1[!#1]? ...
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What does ‘(A)’ mean in SMARTS pattern when using Chemicalize to draw the chemical structure?
I am not quite sure what ‘(A)’ could mean for the carbon atom when writing the SMARTS CCN(C)C using Chemicalize to draw the chemical structure below. Can anyone ...
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Hydrogen oxidation number
I am aware that since 2005, IUPAC guidelines established that hydrogen is more electronegative than all elements from group V in the periodic table (you can check official documentation). Thus, $\ce{...
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1
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What does the dot indicate in the molecular formula for white lead? [duplicate]
I came across the following molecular formula for white lead: $2\mathrm{Pb}\mathrm{CO3}·\mathrm{Pb(OH)_2}$. What does the center dot indicate here? Is this a non-covalent interaction of some kind? ...
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1
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The formula of ammonium phosphomolybdate
It is written in my qualitative chemistry textbook that phosphate could be tested by introducing phosphate, nitric acid and ammonium molybdate which gives (NH4)3H4[P(Mo2O7)6].
I found out in the ...
user139387
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Hydrogen Peroxide 60% Dilution [closed]
Can anyone please help me? I have used various 'dilution' calculators' online, and done the equations on paper. However I DO NOT want to get this wrong and one can be great at math, but help and ...
2
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3
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Minimum molar mass of organic compound with given mass fraction of carbon
Problem from my coaching module:
An organic compound X contains 10% C by mass. The minimum molar mass of compound X is (in g/mol)
100
120
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200
I think the compound must have an integer amount of ...
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Position of H in formula [closed]
I couldn't come to a resolution with these 2 questions that use hydrogen in the middle of a formula that is equipped with a numerical prefix.
Why is is one inside the bracket and one outside? Am I ...
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How's the formula mass of a molecule calculated? Is it the mass in it's empricial formula or molecular formula? [closed]
Like glucose, butane and benzene. How would you calculate their formula mass? Would you calculate it as the mass of their empricial formula or their molecular formula (basically same as molecular mass)...
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betamechaptoethanol smell [closed]
I am doing my masters in science and today one of our neighbors from the other lab came to heat his samples on a heating pad. the samples were in small tubes which contained Betamechaptoethanol, when ...
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Glutaraldehyde or Glutardialdehyde
Recently I was searching for a chemical compound to meet my research needs, i.e. glutaraldehyde, and later I found that Merck has been released different name of compound: (1) glutaraldehyde and (2) ...
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1
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Empirical formula and rounding
I am very confused with the procedure to find the empirical formula. In the part where we have to multiply by subscripts to make them integers, are there clear rules?
For example, if I have the ...
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Number of neutrons in a chemical question?
Consider the equation $\ce{H2 + H2+ -> H + H3+}$
What is the atomic structure of the $H_3^+$ ion? I understand that the H$_3^+$ ion contains 3 protons and 2 electrons. However, how many neutrons ...
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How to write formula for potassium hydrogenpyrophosphite?
I know that pyrophosphite by itself is $\ce {({P_2}{O_5})^{4-}}$. My question is about the hydrogen part- how to know how many hydrogens to add? The answer key for this question says the compound is $\...
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Is there a concise way to calculate pH of a solution after being diluted with water?
I do not have a chemistry degree or even much knowledge in the subject at all. I'm actually an auto detailer and this is why I have an interest in pH levels. All of our chemicals obviously have pH ...
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Resorcinol turned brown [closed]
I stored resorcinol in a transparent plastic container with an airtight lid. There was some air captured inside the container too. After some days, it turned brown. please tell what happened to it?
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How to get the total number of numbered positions in a molecule/compound
I'm working on a metabolite database where "labeled" compounds can contain isotopically labeled atoms in specific positions. When a new labeled compound is entered into the database, we'd ...
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How do I calculate the empirical formula when ash is present in the percentage composition?
I am trying to calculate a chemical formula. How do I calculate the empirical formula when ash is present in the percentage composition?
Example-
C- 47.7%
H- 7.2%
N- 1.8%
S- 0.9%
O- 38.0%
Ash- 4.4%
...
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Reaction between NaCl and NaHCO3 [closed]
Does NaHCO3 (aq) react with NaCl(aq)? I don't think they should undergo any reaction but in the online database it is showing that they react to form Na2CO3 and HCl. Is it correct?
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Why is Pb3O4 called lead(II,IV) oxide?
We know that iron(II,III) oxide has the formula $\ce{Fe3O4}$ which is a combination of iron(II) oxide and iron(III) oxide with formulas $\ce{FeO}$ and $\ce{Fe2O3}$ respectively.
So why isn't this the ...
user85778
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How can the multiplicative number (n) of a chemical series like polyethylene glycol (PEG) be a non-integer?
https://en.m.wikipedia.org/wiki/PEG_400
Down at chemical or molecular formula, it says:
C_2n H_4n+2 O_n+1, like for all polyethylene glycols (PEG)s, but then says n=8.2 to 9.1....
Huh?
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How to find the empirical formula from mass percentages of oxides [closed]
Say you've given an element X and it makes two oxides. The first oxide is $X_\mathrm{4}O_\mathrm{6}$ and the mass percentage of oxygen is 43.7%. In the second oxide, the mass percentage of X is 43.7%.
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Are there examples of molecular formulas with nested groups?
Sometimes a molecular formula is written using groups, for instance $\ce{Al2(SO4)3}$.
Are there examples of formulas with nested groups, such as $\ce{ABC[MNO2(XYZ)4]3}$ or is this avoided?
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Using the mole ratio to figure out the molecular formula [closed]
It takes $\pu{8.0 cm^3}$ of aqueous sodium phosphate to fully react with $\pu{12.0 cm^3}$ of an aqueous solution of the nitrate of metal $\ce{T}$. If both solutions have a concentration of $\pu{1 mol ...
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Combustion analysis of hydrocarbon
Combustion analysis of a hydrocarbon produced 33.01 g CO2 and 4.84 g H2O.
I was asked to find the empirical formula of the hydrocarbon. I used these molar mass values for my calculations:
C - 12.0107
...
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What is the chemical composition of Ferrous Ferrocyanide?
To this day, iron-cyanide complexes confuses me. So, I want to settle this once and for all. After scavenging the internet, I gathered the following result:
$$
\ce{Ferr}
\color{blue}{\ce{ous}}~\ce{...
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How to understand the chemical formula of Prussian blue complex w.r.t its crystal structure?
Note: Just to be clear, I do not refer to "complex molecules" (i.e. "complex" as "complicated"), but to actual complexes.
I am trying to understand the structure of ...
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How can I mix methylene chloride, methanol and hydrofluric acid to make a paint stripper?
HF paint stripper on data sheets lists
Methylene chloride 70>85%
Methanol 10>25%
Hydrofluric acid. 5%
Previously I have found the chemical splits. Is there a particular method to ...
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On basic mercury salts
$\ce{HgCO3.3HgO}$ and $\ce{HgO.Hg(NH2)Cl}$ are called basic mercury carbonate and basic mercury amidochloride, respectively. I found this thread on the former; I've only seen the latter as the product ...
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