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Stoichiometry refers to the relationship between the amounts of substances of the reactants and the amount of substances of the formed products. This tag should be used for specific questions about chemical reaction equations.

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How do I answer part d in the question? [on hold]

The question is referring to 750 L of 3-sulfolene, with a molecular formula of C4H6O2S. When the 3-sulfolene breaks down to form 1,3-butadiene (C4H6) and sulfer dioxide, it gives the balanced equation:...
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If 110.00 mL of 0.500 mol/L sodium sulfate is mixed with 611.11 mL of 0.600 mol/L aluminum nitrate [on hold]

If 110.00 mL of 0.500 mol/L sodium sulfate is mixed with 611.11 mL of 0.600 mol/L aluminum nitrate, what would the resulting concentration of sodium nitrate be?
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How to set up equation for hydrogen ion concentration? [on hold]

If I know a volume of NaOH used to titrate an acidic solution of H+ ions, how would I represent this in an equation? Is it really just $\ce{NaOH + H+ -> Na+ + H2O}$ ? Thanks in advance!
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1answer
25 views

Which container will be yellower? [closed]

Okay this is the question: Now, what will be the answer of 'd'? According to my solution book, this is the answer: So, I didn't understand the solution they gave. I understood that part, if there'...
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22 views

What would be the weight loss equation be for Ketosis? [closed]

This is the formula for how the body uses fat: $$\ce{C55H104O6 + 78O2 -> 55CO2 + 52H2O + energy}$$ From this video: What would be the equivalent formula for Ketosis?From my research ketones can ...
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1answer
19 views

finding out fractions of ions(different valencies/charges) of an element in non-stoichiometric compounds

Analysis shows that nickel oxide has the formula $Ni_{0.98}O_{1.00}$. What fractions of nickel exist as $Ni^{2+} $and $Ni^{3+}$? What i did: Let the number of $Ni^{2+}$ and $Ni^{3+}$ atoms be $x$ ...
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Calculating relative abundance of isotopes

Element $\ce Z$ with an average atomic mass of $\pu{125.20amu}$, has four naturally occurring isotopes, $\ce Z_1$, has a mass of $\pu{121.45amu}, \ce Z_2$, which has half the abundance of $\ce Z_1$, ...
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1answer
34 views

How to distinguish between iron and nickel based on the mass of precipitate formed with sodium hydroxide?

For the reactions shown below, we added $\pu{5.00 mL}$ of $\pu{0.0390 M}$ $\ce{NaOH}$ to a test tube containing one of the two cations $\ce{Ni^2+}$ or $\ce{Fe^3+}$ and recovered $\pu{0.00695 g}$ of ...
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1answer
34 views

Finding the percent by mass of an unknown substance

I'm doing some chemistry homework and a the problem in question goes as follows: "A student performs an experiment to determine the percentage by mass of $\ce{MgCl2}$ in a $\pu{2.94g}$ sample of a ...
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1answer
24 views

How do I identify how many reactions are occurring when precipitating a mixture?

An example of a question is: After dissolving $x$ grams of a mixture of $\ce{Na2SO4}$ and $\ce{NaCl}$ in water, you add an excess of $\ce{BaCl2}$ solution. You filter off the precipitate which ...
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113 views

Calculate the concentration in milimoles per litre (mM) of a solution that is 20% H2SO4 by mass and that has a density of 1.198 g/L

Calculate the concentration in milimoles per litre ($\pu{mM}$) of a solution that is $\pu{20\%} \ce{H2SO4}$ by mass and that has a density of $\pu{1.198 g/L}$. For the answer, please provide two ...
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1answer
97 views

Finding mass percentage of components of a solid mixture

A workbook question asks: $\pu{2.184g}$ of a solid mixture containing only $\ce{K2CO3}$ ($\mathrm{FW = 138.2058}\pu{ g/mol}$) and $\ce{KHCO3}$ ($\mathrm{FW = 100.1154} \pu{g/mol}$) is dissolved in ...
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20 views

Determine molecular formula from % composition and molar mass [duplicate]

A compound's molar mass is 320 g/mol. Its percentage composition is 75.00% carbon, 5.05% hydrogen, and 19.95% oxygen. What is the compound's molecular formula? First, I obtained the empirical formula:...
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3answers
44 views

Copper Stoichometry Ratio Problem

I was given two equations as part of a problem into Copper Wiring production for planes: $$\ce{4CuFeS2 + 9 1/2 O2 + 4SiO2 \rightarrow Cu2S + Cu2O + 2SO2 + 4FeSiO3}$$ $$\ce{Cu2S + 2Cu2O \rightarrow ...
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54 views

Balancing the intermolecular redox reaction

The redox reaction is: $\ce{SO2 + Na2CrO4 + H2SO4 -> Na2SO4 + Cr2(SO4)3 + H2O}$ This is what I tried(tho I got stuck at one point which is indeed the exact reason why I've asked this question): ...
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2answers
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Does a stoichiometric coefficient represent molecules or moles of a substance?

I understand that the one mole of atoms is equal to $6.02\times10^{23}$ atoms. However, when I used various resources to learn about stoichiometry, they showed me a balanced equation: $$\ce{2H2O->...
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1answer
71 views

Concentration of excess reactant

If increasing/decreasing the concentration of an excess reactant influenced the percentage yield of a product experimentally, how could this be explained? I know that in theory, the excess shouldn't ...
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1answer
30 views

Is the kilogram still consistent with the old definition?

My old understanding was that a gram is the amount of mass in a cubic centimeter of water. But then I recently learned that the second was redefined to be some 9 billion cycles of a Caesium atom. ...
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1answer
62 views

Stoicheometry questions: I've been having a bad time not understanding the questions and how the steps are to achieve the answer. please help [closed]

Cetyl palmitate (C32H64O2) is a waxy solid and is the main component of spermaceti, the once prized wax found in the skull of sperm wales. The heads of sperm whales can contain up to 1900 L of ...
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1answer
193 views

Stoichiometric amounts

Can anyone inform me what the term stoichiometric amounts means. I know what stoichiometry means. It is the: The relationship between the relative quantities of substance taking part in a reaction ...
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1answer
79 views

Is it possible for me to derive Avogadro's number?

To my understanding the mole is the unit used to translate between mass on the atomic level and mass in the macro level, defined as the number of atoms in $12$ grams of Carbon-$12$, which apparently ...
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1answer
36 views

Finding empirical formula [closed]

When determining the formula of a compound, why do we divide by the smallest number of moles once we already have calculated the number of moles for each element in order to find the empirical formua ...
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1answer
65 views

How did early chemists measure mass of atoms?

Here a book says that Berzelius measured atomic masses using a simple lab and his measurements was so close to modern results. Can someone explain how a person living in 19th century was able to ...
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1answer
39 views

Is there a formula for density of any gaseous substance just based on its molar mass?

$\pu{112 ml}$ of hydrogen combines with $\pu{56 mL}$ of oxygen to form water. When $\pu{224 mL}$ of hydrogen is passed over heated cupric oxide, the cupric oxide loses $\pu{0.160 g}$ of its weight. ...
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Stoichiometry question regarding Kp and amount

$$\ce{2 NH3 (g) -> N2 (g) + 3 H2 (g)}$$ I know the reaction, temperature (600 Celsius), pressure (1 bar), $K_p$ (equilibrium constant regarding pressure)=16,76, and initial $mol_{reactant}$=1 mol. ...
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1answer
57 views

Heat of Combustion

Methanol ($\ce{CH3OH}$) is regarded by many chemists as a possible liquid fuel for the future. The combustion of methanol occurs according to the equation: $$\ce{2CH3OH(g) + 3O2(g) -> 2CO2(g) +...
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1answer
47 views

How to find the percentage composition of halogen using Carius method?

In the formula: $$\text{Percentage}=\frac{\text{atomic mass of halogen}}{\text{molecular mass of Agx}}\frac{\text{mass of AgX}}{\text{mass of compound}}\cdot100$$ here mass of compound is the mass ...
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34 views

Determining the amount of water in a sample using UV/vis

I have to determine water content in a sample I have measured by UV/vis spectrophotometry. I know what the cation and anion in the compound is. I have an absorbance. I know my compound's mass and the ...
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Stoichiometry yielding negative volume

$15~ \textrm{mL}$ of $4 ~\textrm{N}$ hydrochloric acid, $ 25~ \textrm{mL}$ of $2~ \textrm{M}$ $\textrm{H}_3\textrm{PO}_3$ and a certain volume of $2.5~\textrm{M}$ sulphuric acid are mixed together and ...
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36 views

Why doesn't this question violate the conservation of mass?

Combustion of of $0.255 \space g$ of isopropyl alcohol produces $0.561 \space g$ of $\ce{CO_2}$ and $0.306 \space g$ of $\ce{H_2O}$. Determine the emperical formula of isopropyl alcohol. I'm not ...
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KCl + CuCl2 in solution, is there a reaction?

I'm wondering if the reaction of $\ce{KCl + CuCl2}$ in solution (aq) will produce any products (have a net ionic equation/solid precipitate)? Using the metal activity series, I see that potassium is ...
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1answer
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Balancing the reaction of potassium permanganate and sulfuric acid with hydrogen peroxide [duplicate]

A problem on redox reactions invites the reader to balance the actual reaction from which the redox simplification arose. After some hunting I found the balanced equation and attempted to re-derive ...
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1answer
29 views

Find amount of benzoic acid in dissolution

Solubility of benzoic acid in water at $\pu{0^\circ C}$ is $\pu{1.7 g/L}$ and given the fact that $\pu{37 mL}$ was used to dissolve $\pu{1 g}$ of benzoic acid. How much of the benzoic acid would be ...
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Is there always a limiting reagent in every equation?

Is there always a limiting reagent in every equation? For instance, is there a limiting reagent in $\ce{CaCl2 + Na2CO3 -> 2NaCl + CaCO3}$ where the same number of moles are reacting with each ...
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Mathematically balancing chemical equation yields weird results

I found this equation while testing my equation balancer: $$ \ce{a C7H6O3 + b C4H6O3 -> c C9H8O4 + d C2H4O2} $$ Obviously, $a = b = c = d = 1$ is a solution. However, if we were to bring in some ...
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2answers
865 views

What is the difference between ''1 C atom and 1 mole of C atoms?'' [closed]

Does 1 C atom mean 1 single C atom out of Avogadro's number of C atoms = 1 single C atom out of 6.023 X 10^23 numbers of C atoms? Does 1 mole of C atoms mean Avogadro's number of C atoms = 6.023 X 10^...
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What to say 'one mole of C atoms or one mole of C molecules?

What to say 'one mole of C atoms or one mole of C molecules in CO? Please point out if I am wrong here As we know, one molecule of CO = one mole of CO molecules = 6.223 X 10^23 number of CO molecules ...
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How much sodium hydroxide powder do I need to add to get a new pH?

I want to increase the pH of a $\pu{300 ml}$ deionised water solution from 7 to 11. How much sodium hydroxide should I add? I have tried this but the answer doesn't seem correct (because it's so small)...
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1answer
286 views

What is the molecular formula of the hydrocarbon? [closed]

A hydrocarbon is burnt completely in excess oxygen to produce 0.04 mol of carbon dioxide and 0.72 g of water. What is the molecular formula of the hydrocarbon?
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Finding the volume of gaseous product will be generated at STP upon the combustion of TATP?

Question: The combustion of TATP ($\ce{C12H24O8}$)follows the balance equation: $$\ce{C12H24O8 (s) +14O2 (g) -> 12CO2 (g) + 12H2O (g)}$$ If $\pu{592.6 g}$ of TATP is combusted in excess ...
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How to balance this manganese peroxide reaction with hydrogen peroxide? [duplicate]

I have the following equation, already written, with a few coefficients to write. $\ce{2MnO4^- + a H2O2 + b H+ -> 2Mn^2+ +c O2 + dH2O}$ I have put a = 1, b = 6, c = 3 and d = 4. The number of ...
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What is the volume of the produced SO2 gas at STP? [closed]

In a electricity producing plant $3.1\times10^7\ \mathrm{kg}$ coal with $2.4\ \%$ rhombic sulfur is burnt every year. What is the volume of the produced $\ce{SO2}$ gas at STP? My effort for solving ...
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Determination of Sorbitol in Diabetic Marmalade

A sample of diabetic marmalade ($\pu{0.100 g}$) after suitable treatment, was titrated with aqueous sodium iodate(VII) ($\pu{1.00 mol dm^-3}$), and $\pu{1.63 cm^3}$ of titrant was required for ...
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77 views

Calculate the formula, and moles

If $\ce{1.84\times10^{-4}}$ moles of element A was completely reacted with element B to create $\ce{1.231\times 10^19}$ molecules of $\ce{(A3B2)_x}$ a hypothetical compound, what is the value of x? I ...
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Molecular formula and decimal number

Today I did some stoichiometry exercise about finding the ratio between the elements. What confused me was that while the ratio was right, but it was decimal. Ex. Reducing $\pu{0.800 g}$ of lead ...
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1answer
44 views

Where am I wrong in my calculations? [closed]

I am revisiting the concept of mole and I decided to figure out random values (for instance: mass of 1 molecule of water) to see how much I understand the concept of moles and how it relates to amu. ...
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523 views

How to find the molar mass of an iron compound based on its mass and mole fraction in the compound?

I'm trying to solve this question: We have a molecule composed of $3$ iron atoms, and $4$ atoms of another element. We are given the following information: it has $\pu{2.36 g}$ of iron for $\pu{3....
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1answer
57 views

Stoichiometry of incomplete combustion

Methane is burned with air in a continuous steady-state combustion reactor to yield a mixture of carbon monoxide, carbon dioxide and water. The feed to the reactor contains: $\pu{7.8 mole \% }\ce{...
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293 views

How can the number of moles in the product side be more than reactant?

A rigid stainless steel chamber contains $\pu{0.32 bar}$ of methane, $\ce{CH4}$, and excess oxygen $\ce{O2}$, at $\pu{200.0 °C}$. A spark is ignited inside the chamber, completely combusting the ...
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284 views

How to determine the mass of sodium chloride and volume of a 1 M silver nitrate solution necessary to produce a given mass of silver chloride?

Determine how much $\pu{1 M}$ $\ce{AgNO3}$ solution and $\ce{NaCl}$ is needed to produce $\pu{1.25 g}$ of $\ce{AgCl}$. The balanced equation is $$\ce{AgNO3 + NaCl = AgCl + NaNO3}$$ and the molar ...