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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Dilution Formula for NH4OH [closed]
I need this for an experiment:
ca. 3 mL concentrated (15 M) aqueous ammonia solution, NH3 (from a dropping bottle.)
I have the NH4OH pictured below. How can I dilute it to get what I need? What is the ...
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3
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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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2
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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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3
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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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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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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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0
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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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2
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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 ...
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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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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%.
...
4
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2
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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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1
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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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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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2
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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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7
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1
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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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1
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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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1
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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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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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2
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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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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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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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Are atom coordinates in molfile necessary to produce a valid InChI identifier
I took this molfile of benzoic acid:
...
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1
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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's the chemical reaction between coffee and sodium bicarbonate? [closed]
Every morning I put sodium bicarbonate into my coffee and I was wondering what chemical reaction this produces and what are the chemicals produced at the end.
I cannot find an answer to this question ...
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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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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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0
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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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1
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0
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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 ...
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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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What is the chemical formula of ghee? [closed]
What is the chemical formula of ghee (Indian butter)? Also, name the elements present and state the number of their atoms.
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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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0
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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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0
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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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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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Lewis structures and chemical-compound formulas [closed]
In the Lewis structures listed below, M and X represent various elements in the third period of the periodic table. Write the formula of each compound using the chemical symbols of each element:
a.
b.
...
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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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1
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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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I am having trouble with this question on net ionic equation [closed]
Convert into molecular equation:
The reaction between potassium dichromate, ferrous sulphate and sulphuric acid:-
Cr2O7^2- + 14H^+ + 6Fe^2+ ---> 6Fe^3+ + 2 Cr^3+...
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0
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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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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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1
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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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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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1
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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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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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