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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I am once again confused about Avogadro's number [closed]
How is the molar mass of a substance numerically equal to its relative atomic mass? Can someone explain this to me, please?
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What does the term gram atoms in chemistry mean? How much volume does 1 gram atom of nitrogen contain? [duplicate]
I came across a question in my ALLEN module, I was practicing questions on mole concept. So, the question is, 1g atom of nitrogen represents : a) 6.023 x 10^23 N2 molecules
b) 22.4L of N2 at 1atm and ...
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Calculation of the retained mass after hydrolysis of an oligopeptide
I would like to ask about a problem that I am stuck on:
An oligopeptide is made up of glycine, alanine, and valine. Hydrolysis of X in $\pu{500 mL}$ of $\pu{1 M}$ $\ce{H2SO4}$ solution yields ...
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How to calculate carbon to phosphorus stoichiometric ratios using results from ICP-MS and CHN analyzer?
I run a few chemostats to manipulate the carbon to phosphorus ratio (C:P) of algae, which is later feed to an invertebrate. I used Inductively coupled plasma mass spectrometry (ICP-MS) and Inductively ...
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What is the meaning of "maximum" weight produced after series ot reactions?
$4.14$ grams of a piece of lead was made to react with $\ce{HNO3}$ so as to produce lead nitrate. Lead nitrate further reacts with a series of reagents to form $\ce{(NH4)2PbCl6}$. Then find the ...
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What are some efficient approaches for balancing long chemical equations? [closed]
I am having some difficulties in balancing chemical equations involving many elements. It takes a lot of time (for me) to balance the coefficients using the hit and trial method. Especially like this ...
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A reaction based question from stoichiometry [closed]
A 110.0g sample of a mixture of CaCl2 and NaCl is treated with Na2CO3 to precipitate the Calcium as Calcium Carbonate. This CaCO3 is heated to convert all the Calcium into CaO and the final mass of ...
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Why is Fe3O4 a non-stoichiometric compound? [closed]
Fe combines with O in a whole number ratio 3:2. Even the ions Fe2+ and Fe3+ are in the ratio 1:2. Then, why Fe3O4 is a non-stoichiometric compound?
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How would you find the Q value in the Nernst equation if you were to change the temperature?
I'm studying how changing the temperature of the anode would affect the voltage produced within a galvanic cell. I think that the Nernst equation plays a role here but I am unsure how the reaction ...
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Finding the molecular formula given combustion data
$\pu{150 cm^3}$ of oxygen were added to $\pu{20 cm^3}$ of a gaseous hydrocarbon D.
After explosion and cooling, the gaseous mixture occupied $\pu{130 cm^3}$
and, after absorption by potassium ...
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Calculate volume of hydrogen gas evolved
MCQ Question:
Ammonia borane in water can release hydrogen upon hydrolysis while forming NH4BO2 as the other
product.
The volume (cm3) of hydrogen gas which will be evolved from the hydrolysis of 309 ...
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Finding concentration of ascorbic acid
Question:
A person applied following procedure for the determination of ascorbic acid (Vitamin C) in a sample solution.
A volume of 20.00 cm3 of the ascorbic acid sample was reacted with 25.00 cm3 of ...
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UV absorbance titration to determine binding stoichiometry
I previously posted a question but I think I did not explain correctly. I want to construct a Job plot using UV-Vis titration to find binding stoichiometry. I have 20uM of ligand solution and 20uM of ...
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Find percentage of carbon monoxide reacted using ideal gas equation
Question
A palladium or platinum catalyst was used in an automobile to convert carbon monoxide gas to carbon dioxide according to the following reaction:
$$\ce{2CO(g) + O2(g) -> 2CO2(g)}$$
A ...
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Calculating required mass of reactant to produce a specific product
I want to know how many grams of $\ce{C}$ (carbon) are required to create $\pu{58 grams}$ of $\ce{Na2S}$, given
$$\ce{Na2SO4 + 2C -> Na2S + 2CO2}.$$
First I calculated molecular mass of $\ce{Na2S}$ ...
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What is mol % and how do you calculate the mass of a compound needed to be a certain mol % relative to another compound at a particular volume? [closed]
I know that there is some stoichiometry involved, but I am lost here. I know you need the molecular weight of both compounds and that's about it?
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Find the added volume of HCl so that the ions separate
Suppose we have a 10mL solution that contains 0.02M $\ce{Ag^+}$ and 0.04M $\ce{Ba^{2+}}$. a) Find the necessary volume to be added of $\ce{HCl}$ to separate all the silver. (Assume to be separated if ...
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Does stoichiometric gas mixture produce the highest explosion pressure (or energy) compared with other explosive limit mixture?
I understand that a stoichiometric mixture contains a balanced mixture of air and fuel and both fuel and air are completed consumed. For example, the ideal stoichiometric mixture for propane is ...
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What's the stoichiometric ratio of Kerosene to a mixture of 50% water and 50% hydrogen peroxide [closed]
So I'm wanting to do some testing with combustion of certain liquids, and I'd like to know what the right ratio is for these liquids. What I'm going to be using is regular kerosene (NOT RP-1) and 50% ...
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Find the required water volume to add so that the pH of two solutions will be the same
Question.
We have two flasks: one contains 50 mL of 0.001 M HCl and the other 50 mL of 1M acetic acid.
a) How much water should be added to the more acidic solution so that the pH of the two ...
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Store Palladium Chloride in Solution
I have one gram of palladium chloride ($\ce{PdCl2}$) and I want to use very small quantities of it, in milligrams somewhere. It is not possible for me to get my hands on a scale that can measure that ...
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What is the difference between a single displacement reaction and a two competing reaction system?
For example, consider the single-displacement reaction
$$\ce{AB + C <=> BC + A}$$
My question is then if writing this reaction as the system
\begin{gather}
\ce{AB <=> A + B} \\
\ce{B + C &...
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Balancing a redox reaction equation with a mystery reactant
The answer to the following question from NSAA 2021 Chemistry Section 2 is C.
Consider the following chemical equation:
$$\ce{vQ + wP4 + x H2O -> yPH4I + zH3PO4}$$
where Q is a binary compound.
...
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Should durations of time be considered to determine final significant figures of answer?
In preparation for AP Chemistry this upcoming semester I've been assigned a number of challenge problems. One of them is as following:
Suppose that polluted air has carbon monoxide $(\ce{CO})$ levels ...
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Stoichiometric coefficients in reaction between vanadium(II) oxide and iron(III) oxide
Calculate the weight of $\ce{V2O5}$ produced from $\pu{2g}$ of $\ce{VO}$ and $\pu{5.75 g}$ of $\ce{Fe2O3}$
Now we write the reaction as following - $$\ce{2 VO + 3Fe2O3-> V2O5 + 6FeO}$$
Now, by the ...
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Are chemical equations like a cooking recipe?
Sometimes, balanced chemical equations are compared to cooking recipes. Here is one example:
Imagine if you were baking chocolate chip cookies and measured out your ingredients incorrectly. What if ...
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Difference between change of enthalpy of neutralization between copper and manganese carbonate
I was doing a calorimetry experiment to calculate the change in enthalpy during neutralization reactions between metal carbonates and hydrochloric acid. I experimented with 5 metal carbonates: ...
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What will be the product of 1 eqv Benzene reacts with 1eqv H2? [closed]
how equivalent concept is applied in the above problem, Kindly help me out with the answer and proper explanation.
As, I am getting confused in mole concept and equivalent concept here.
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Finding the density
35.6g of NaOH is dissolved in 150g of 20% NaOH solution. What is the density od the solution?
I have tried solving this problem, but I 've come across a few obstacles.
Firstly, I found the mass of ...
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Why is the relationship between a compound in its elements expressed in moles or particles? Is there a law dedicated to this? [closed]
I understand that a ratio can be made for the number of elements in a compound and the actual compound. Depending on the need, different units can be used. It can be both moles. It can also be ...
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Do you always need to balance a chemical equation to find the percentage yield and limiting reagent?
I'm doing some problems through MIT open courseware and I've got one I'm absolutely stuck on. It details a three-step synthesis for hyperzine A, gives molecular weights and diagrams for individual ...
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How do you write fractional hydrates in words?
Apart from sequihydrate and hemihydrate (1.5 and 0.5 respectively), I can't find a way to write any other fractional hydrates.
Wikipedia states:
The notation "hydrated compound⋅nH2O", where ...
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If sulfur is directly below oxygen on the periodic table, why isn't SO the most common sulfur oxide? Instead of third, behind SO2 and SO3? [closed]
Chalcogen like oxygen and sulfur want to 'grab' (or share) two electrons to get to eight, if possible, or maybe 'give up' (or share) six, if necessary, to again get to eight... Right?
So, why is ...
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Nylon 6,6 synthesis yield
This is the nylon 6,6 reaction
Having these data available, I would need to know the theoretical quantities, in grams, of the monomers
My attempt:
Adipoyl chloride is our limiting reactant so ...
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Finding masses of the products for halogenation of benzene from percent yields
We provide a reactor $\pu{90 kg}$ of benzene and $\pu{30 kg}$ of $\ce{Cl2}$.If the percent yield of the first reaction with respect to benzene is $25\,\%,$ and the percent yield of the second reaction ...
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Is there a need to change sign for enthalpy value for a reaction that appears in reverse when using Hess's law?
Problem
Given the enthalpies of the following reactions
\begin{align}
\ce{2H(g) &-> H2(g)} &\quad \Delta_\mathrm{r}H^\circ &= \pu{-437.6 kJ mol^-1} \tag{R1}\\
\ce{C(s) + 2 H2(g) &-&...
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How is 1 mole hypochlorite ion equivalent to 1 mole chlorine gas?
According to my book, 1 mole ClO- is equivalent to 1 mole Cl2. How is that even possible? 1 mole ClO- contains 1 mole Cl atoms. On the contrary, 1 mole Cl2 gas contains 2 mole Cl atoms. So, how are ...
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Should I write formula for oxalate or oxalic acid while balancing a redox reaction using the ion-electron method?
Problem:
Balance the following reaction using the ion-electron method:
$$\ce{H2C2O4 + KMnO4 + H2SO4 -> CO2 + MnSO4 + K2SO4 + H2O}$$
My book's solution:
Oxidation half-reaction:
$$\ce{C2O4^2- -> ...
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Why did my book write S2- if hydrogen sulfide isn't ionic?
Problem:
Balance the following reaction using the ion-electron method:
$$\ce{KMnO4 + H2SO4 + H2S -> MnSO4 + S + K2SO4 +H2O}$$
My book's solution:
Oxidation half-reaction:
$$\ce{S^{2-}->S + 2e^{-}...
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Convention for writing concentration units
1st part of my question:
Q) The concentration of an NaCl solution is 1M. Express this in percent wt. by vol. unit.
Ans:
$$\text{In %(w/v) unit}=\frac{58.5\pu g}{1000\pu{mL}}\times \frac{100}{100}=5.85\...
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What will happen if the electrolysis of Brine takes place for a long time?
This is the reaction:
$$\ce{2NaCl(aq) + 2H2O(l) -> 2NaOH(aq) + H2(g) + Cl2(g)}$$
If the above reaction goes on for long enough, we will eventually run out of Cl- ions. There will only remain an ...
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Balanced reaction to Cr given H+ [closed]
The troublesome nature of this post, is that I was given very little information to work with:
"The metal chromium (Cr) reacts with an acid, to create Cr^+3 ions, and hydrogen gas.
Show the ...
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How much Calcium Hydroxide to manufacture calcium formate?
First, I have no experience with stoichiometry.
I currently manufacture calcium formate for a specific use because here in my country, it is very difficult to get calcium formate in small quantities. ...
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Atomic formula obtained by mixing given percentages of oxides
Calculate the atomic formula of a compound which is made by
$93\,\%$ of $\ce{SnO2}$ and $7\,\%$ of $\ce{Sb2O5}$.
The molar mass of $\ce{SnO2}$ is $\pu{150.71 g mol^-1}$ and the molar mass of $\ce{...
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When balancing equations, how do we handle chemicals in different states of matter?
Balancing chemical equations such as $$\mathrm{H_2 + O_2 \to H_2O}$$ or $$\mathrm{NaHCO_3 + H_3C_6H_5O_7 \to Na_3C_6H_5O_7 + H_2O + CO_2}$$ seems to be easy enough by finding the coefficients of each ...
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What does n(Na2CO3) mean?
In my book, $n(\ce{Na2CO3})$ was used to indicate the number of moles of $\ce{Na2CO3}$ without any clarification. Is it common knowledge among chemists that $n(\ce{Na2CO3})$ indicates the number of ...
user119245
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How to correctly use the avogadro number? [closed]
Avogadro constant, $N_A$ is equal to $\frac{6.02214076 \cdot 10^{23}}{mol}$. There is no unit of particle or anything in $N_A$ (nothing like $N_A = \frac{6.02214076 \cdot 10^{23} \ce {particles}}{mol}$...
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How can one determine if a chemical reaction is impossible to balance?
I asked this question on Math Stackexchange, but thought I'd get a more chemical view:
https://math.stackexchange.com/questions/4326904/determining-whether-or-not-a-system-of-equations-has-nonzero-...
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Using the mole ratio to figure out the molecular formula [closed]
It takes $\pu{8.0 cm^3}$ of aqueous sodium phosphate to fully react with $\pu{12.0 cm^3}$ of an aqueous solution of the nitrate of metal $\ce{T}$. If both solutions have a concentration of $\pu{1 mol ...
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How is formula for mean ionic activity derived from its constituent activities?
I spent hours in order to understand the following - but without success:
At many places the mean ionic activity coefficient for the reaction
$$\ldots \rightarrow \nu_A A^{z_A+} + \nu_B B^{z_B-}$$
...
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