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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How to calculate the number of hydrogen atoms present in 40g of urea (NH2)2CO [closed]

Quantitative Aspects of chemical change
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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 ...
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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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5 votes
2 answers
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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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How is MgSO4 a neutral salt? [duplicate]

So the reaction for forming MgSO4 involves two reactants: H2SO4 and Mg(OH)2, However, the salt formed is netural. Even though H2SO4 is a strong acid and Mg(OH)2 is not a strong base. Shouldn't the ...
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1 vote
1 answer
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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 answers
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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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6 votes
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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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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 answers
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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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6 votes
1 answer
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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 answer
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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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1 answer
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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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1 vote
1 answer
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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 answer
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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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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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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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1 vote
1 answer
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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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1 answer
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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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2 votes
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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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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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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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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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-3 votes
1 answer
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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 answer
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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 answer
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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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1 vote
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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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3 answers
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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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2 votes
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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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3 votes
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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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3 votes
1 answer
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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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3 votes
1 answer
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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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