# Questions tagged [stoichiometry]

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 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 ...
0answers
51 views

### 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 ...
1answer
38 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 ...
2answers
2k views

### 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 ...
1answer
4k views

### 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 ...
1answer
48 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 ...
3answers
5k views

### 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 ...
1answer
124 views

### 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 ...
2answers
1k 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^...
1answer
211 views

### 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 ...
1answer
643 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?
1answer
287 views

### 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 ...
1answer
399 views

### 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 ...
1answer
87 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 ...
2answers
494 views

### 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 ...
1answer
57 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. ...
2answers
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### 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 ...
3answers
1k views

### Unknown notation relating to stoichiometry

I have never seen the highlighted symbol before. What is the name of the symbol itself, and what does it mean in this context?
2answers
152 views

### Weight of sodium acetate required to get to certain pH

How many grams of $\ce{CH3COONa}$ we need to dissolve in $\pu{2.50 L}$ of water to get a solution with $\mathrm{pH} = 9.00$? Given $K_\mathrm{a}(\ce{CH3COOH}) = 1.75\cdot 10^{-5}$ Like solving a ...
1answer
1k views

### Mixing Ca(OH)2 with Ca(NO3)2

Mixing $\ce{Ca(OH)_2}$ with $\pu{0.1 M}$ concentration of $\ce{Ca(NO3)2}$. What will actually happen in the process? What I will see with my eyes? I know that $\ce{Ca^2+}$ cation with concentration ...
1answer
396 views

### Stoichiometry question

I tried solving the following question but am not sure I did so correctly and simply wished to verify it here. In 50.3 gr of a compound whose formula is $Na_2X_4O_7$ (where X is an unknown atom) are ...
1answer
51 views

### Can i calculate the solution of the problem in more simple way?

and i got a serious question. During my exercises at home, i found that im struggling a lot while solving simple problem`s like this one: I have an aquatic substance with 0.100 M of $\ce{Mg(NO3)2}$ ...
1answer
318 views

### Equivalent weight of the anhydrous acid [closed]

The cupric salt of a monobasic acid contains $3$ molecules of water of hydration per atom of $\ce{Cu}$. $\pu{1 g}$ of hydrated salt yielding on strong heating $\pu{0.3306 g}$ of $\ce{CuO}$. What is ...
1answer
133 views

### Mass of iron from the reduction of iron(III) oxide [closed]

Given the equation $$\ce{Fe2O3 + 3H2 -> 2Fe + 3H2O},$$ determine how many grams of $\ce{Fe}$ can be produced from $\pu{16.5 g}$ of $\ce{Fe2O3}$. I've already determined the masses of each ...
1answer
174 views

### Volume of nitrogen gas produced during taking off

The fuel in the buster rockets of the Space Shuttle is constituted of a mixture of ammonium perchlorate, $\ce{NH4ClO4}$, and aluminum powder. One of the reactions taking place during taking off is ...
1answer
102 views

### How much additional hydrochloric acid should be added to arrive at ‘excess acid’?

I am an IB student. And I am trying to find the mass percentage of $\ce{NaHCO3}$ in antacid. I am dissolving the antacid in $\pu{0.1 M}$ $\ce{HCl}$ solution. So, first of all I conducted some ...
0answers
205 views

### Validity of Law of Equivalence

Is law of equivalence valid for partial displacement reactions? 【I found this in my textbooks: According to the law of equivalence, whenever two substances react, the equivalents of one will be equal ...
1answer
145 views

### Is there a specific chemical reaction between capsaicin and casein? Is there a stoichiometric relationship between them? [closed]

I am trying to establish the reaction between capsaicin and casein in order to neutralize the effects of the capsaicin. Therefore, I must determine if there is a reaction and a stoichiometric relation....
2answers
138 views

### Neutralization of alkali solution by a mix of strong acids

$\pu{0.1 M}$ $\ce{HCl}$ and $\pu{0.2 M}$ $\ce{H2SO4}$ solutions are mixed in equal volume. This solution is diluted to double the volume. Find the volume of $\pu{0.1 M}$ $\ce{NaOH}$ which can be ...
1answer
61 views

### What are the percentages of isotopes? [duplicate]

The average atomic mass of a sample of an element 'X' is 16.2u. What are the percentages of isotopes $\ce{^16_8X}$(atomic number = 8, atomic mass = 16) and $\ce{^18_8X}$(atomic number = 8, atomic ...
1answer
131 views

### Uncertainty in measuring the mass of the palm oil and the base in saponification

I am a student coming from the domain of mathematics, and I am working on error analysis and uncertainty, but I have a question in the domain of chemistry. I am studying the effect of the ...
1answer
1k views

### Confusion in n-factor calculation

How do we calculate the equivalent weight of a compound, in a case where certain fraction of an element of the compound is getting reduced, while the other fraction is unaffected (no change in ...
2answers
241 views

### Calculation for buffer of pH 5 in sodium fluoride solution

From a journal: $\pu{500 mL}$ of $\pu{50 ppm}$ fluoride at $\mathrm{pH}~5$ was prepared by mixing $\pu{0.0552 g}$ of sodium fluoride with $\pu{4.1057 g}$ of sodium acetate and $\pu{1.65 mL}$ of ...
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1answer
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### Calculating n factor of SO2

I'm having a hard time trying to figure out n factor of $\ce{SO2}$ in the reaction $$\ce{FeS2 + O2 → Fe2O3 + SO2}\qquad \text{(unbalanced)}$$ To balance it, I saw that in 1 mole of $\ce{FeS2}$, it ...
1answer
497 views

### Concentration of ammonium phosphate if dissolved in water [closed]

If $\pu{2.54 mg}$ of ammonium phosphate is dissolved in enough water to make $\pu{300 mL}$ of the solution, what is the molar concentration of the solution? The answer is $\pu{5.68e-5 mol L-1}$. ...
1answer
89 views

### Concentration of mercury in body

Symptoms of mercury poisoning become apparent after a person has accumulated $\pu{20 mg}$ of mercury. If a person ingested $\pu{30 mg}$ of mercury, what concentration of mercury in parts per million, ...
1answer
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0answers
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### Can I approximate the CO concentration of a combustion product, if I know the CO2 and O2 concentration?

Assume I have the product (exhaust gas) from a combusted air/petrol mix. The mixing ratio was richer than stoichiometric (i.e., air:fuel < 14.67 in this case), so there was no excess of oxygen. I ...
1answer
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### Where to find good worksheets for balancing chemical equations

I am preparing for the Chemistry SAT in a couple of weeks. I am looking for worksheets like this that will give me practice balancing complex chemical equations with lots of compounds. Is there any ...
1answer
784 views

### Finding average Mr of a gaseous mixture

A 2 g mixture of cyclohexanol, acetone and pentanal is completely burnt in oxygen. When the gaseous product is passed through $\ce{P2O5}$, the mass of $\ce{P2O5}$ increased by 1.998 g. Find the ...
0answers
150 views

### Problem regarding failure of equivalence concept

Chile salt peter, a source of $\ce{NaNO3}$ also contains $\ce{NaIO3}$. The $\ce{NaIO3}$ can be used as a source of iodine, produced in the following reactions. \begin{align} \ce{IO3- + 3 HSO3- &...