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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What is the maximum number of water molecules that has been recorded till date to present as water of crystallization in a compound?
Context: I was casually looking through some old questions when I found this question. The OP wanted a compound that has all the hydrates ranging from monohydrate to decahydrate. I found chromium(III) ...
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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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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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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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Are atom coordinates in molfile necessary to produce a valid InChI identifier
I took this molfile of benzoic acid:
...
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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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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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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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Can two positive ions be next to each other in a formula?
Let's say I want to find the oxidation numbers of the atoms in a chemical formula.
For example: In $\ce{H3AsO3}$,
Oxygen has a $-2$ charge. They're $3$ of them, so its $-6$
Hydrogen has a $+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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Chemical formula of a compound crystallized in a cubic lattice
Question
In a cubic lattice of $\ce{XYZ},$ $\ce{X}$ atoms are present at all corners except one corner which is occupied by $\ce{Y}$ atoms. $\ce{Z}$ atoms are present at face centres. What is the ...
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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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Ratio of copper(II) ions to EDTA?
What is the ratio of copper(II) ions to EDTA in a $\ce{[Cu(EDTA)]^{2-}}$ complex?
I know that EDTA forms up to 6 coordinate bonds with the central atom, but is that what they are asking for with "...
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What's the difference between Zinc Ascorbate and Zinc Gluconate?
I've been looking at a dental product for pets, called MAXI/GUARD Oral Cleansing Gel and it states it uses zinc ascorbate/taurine, however in the ingredients I found elsewhere it instead lists zinc ...
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Empirical and molecular formula
I was doing a homework assignment and I got the question wrong because I was supposed to multiply the empirical formula of $\ce{C6H10S2O}$ by 3 to get the molecular formula.
I put $\ce{(C6H10S2O3)3}...
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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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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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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)
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I think the compound must have an integer amount of ...
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What does fractional notation represent in molecular formulas such as SiO4/2 or H2SiO2/2?
I'm going through some papers about HSQ (hydrogen silsesquioxane) and keep seeing this fractional notation being used:
HSiO3/2 , SiO4/2 , H2SiO2/2 , H3SiO1/2.
Example paper.
I understand that the ...
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How to use NMR readings to determine the molecular structure of a compound? [closed]
A question in my exam came as follows:
How is NMR used in the determination of structure of organic compounds?
I have studied NMR spectroscopy and I know how to determine values using an NMR ...
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1
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Si(OH)4 vs. H4SiO4 vs. SiO2.2H2O
Can someone please explain to me what is the differences between $\ce{Si(OH)4}$, $\ce{H4SiO4}$, and $\ce{SiO2.2H2O}$? I am currently studying sandstone acidizing geochemical models and this question ...
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1
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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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Finding formula of reduced scandium oxide using its mass and mass of obtained metal
An oxide of scandium, with a mass of $\pu{1.423 g},$ is chemically reduced with $\ce{H2}$ to give $\ce{H2O}$ and $\pu{0.929 g}$ of $\ce{Sc}$ metal. What is the formula of scandium oxide? How much ...
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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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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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What are the additional chemicals required to make polyurethane foam more viscoelastic? [closed]
I am currently experimenting with polyurethane forms for a science and research project I am working on. I need to make the polyurethane foam more viscoelastic, almost like memory foam. I am unable to ...
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Determining the number of triphenylphosphine ligands in nickel(II) complex
A complex is synthesised by combining hydrated solutions of $\ce{NiCl2}$ $(\pu{0.6 g})$ with $\pu{1.35 g}$ triphenylphosphine $(\ce{PPh3}).$ After cooling the product precipitates as a solid with ...
user85551
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Kinetics of Decomposition of Hydrogen Peroxide [duplicate]
Consider the decomposition of Hydrogen Peroxide:
$$\ce{H2O2 -> H2O + 1/2O2}$$
The rate law for this reaction is :
$$\text{Rate} = k[\ce{H2O2}]$$
Further
$$\text{Rate} = -\frac{\mathrm d[\ce{H2O2}]}...
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The equation representing the dissolution of cycasin [closed]
Is the following equation correct?
$$\ce{{C_8H_{16}N_2O_7}_{(s)} + H2O_{(l)} <=> {C_8H_{16}N_2O_7}_{(aq)}}$$
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What is the materials science behind thermal diffusion in multispectral camouflage?
I've been interested in infrared and near-infrared camouflage (called multispectral camouflage) for a couple of days now, and I've found a video or two of certain companies that have created fabrics ...
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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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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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Separating Silica from silicates [closed]
Does anyone know how one could extract Silica $\ce{SiO2}$ from a one or more of the following compounds in either ground or powder forms?
Plagioclase: $\ce{Ca2Al2Si2O8}$
Pyroxene: $\ce{(Ca,Mg,Fe)...
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1
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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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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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How to interpret this formula about hydrogen bond energy
I want to evaluate some chemistry related formulas, which I don't understand.
In proteins, hydrogen bonding often occurs between the oxo group = O oxygen of one amino acid and the α-amino group (N − H)...
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What is the chemical formula for the synthesis of Hydroxyapatite (Ca10(PO4)6(OH)2)?
This might be a basic question but I am a little confused.
I have some lecture notes that says calcium phosphate ($\ce{Ca3(PO4)2}$) reacts with calcium hydroxide ($\ce{Ca(OH)2}$) to form ...
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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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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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Chemical reaction of bronze tarnishing
Can anyone explain to me the chemical process of bronze tarnishing? According to Wikipedia:
Bronzes are typically ductile alloys, considerably less brittle than
cast iron. Typically bronze oxidizes ...
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What is one formula unit? [duplicate]
I am really sorry if this is a beginner question but please still help me.
In this website, which explains balancing chemical equations mentioned the word formula unit here:
$\ce{3Ca(NO3)2}$ (just ...
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1
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How is Potassium present in Potato (form) and where does it come from originally? [closed]
I was going through the concept of Boiling to reduce the potassium in Potatoes, which means $\ce{potato + water +heat -> potassium + X}$. $\ce{X}$ is potato with reduced potassium. I am more ...
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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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What's the effect of Pressure change in Chemical Equilibrium if any reactant or product is Solid or Liquid?
I am studying La-Chatelier's Principle of Chemical Equilibrium. I got a problem of Pressure change in Chemical Equilibrium.
I know that Pressure change If a reversible reaction is in equilibrium ...
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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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Sucrose skeletal formula - missing Carbon and Hydrogen [duplicate]
I was reading the Wikipedia article about Sucrose, when I noticed that the skeletal formula was missing some $\ce{C}$ and $\ce{H}$ atoms. The chemical formula being $\ce{C12H22O11}$, I counted the $11$...
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1
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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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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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