Stoichiometry Calculator To Balance Chemical Equation Online

The role of the free online Stoichiometry Calculator in balancing chemical equations is critical as it assists to explain all the chemical reaction steps in detail. The role of Stoichiometry is to balance the proportional quantities of the reactant and the products in a chemical reaction. Thus, the stoichiometry calculator makes it possible to balance chemical equations.

As well as their proportional ratio at a specific time of the reaction. It is essential for the learners to first completely understand the concept of Stoichiometry. Stoichiometry enables us to determine the result of the reaction before it is carried out, by entering the data in the stoichiometry formula. This result is used to mix the specific concentration of the reactants.

In particular, to attain the specific molar concentration of the products. Simply put, Stoichiometry is a section of chemistry to get the desired quantitative product by using the proportional quantities of the reactant. In Greek, the word  “Stoikhein” means the elements, and the “Metron” means the elements. Thus, we can literally derive the Stoichiometry meaning.

Whereby, the actual meaning of Stoichiometry is the determination of the proportional qualities of the reactant and the product. More so, according to the “law of the conservation of mass”. That said, let’s learn how it’s calculated.

Understanding Why The Stoichiometry Calculator Is Important

As mentioned, the Stoichiometry Calculator is used to balance the chemical equations on both sides. It takes the chemical equation as input and outputs a balanced equation with the equilibrium constant and many other properties of the reactants and products. Stoichiometry defines the relationship between the reactants and products by balancing their components.

With the rise of technological advancements, you can easily and quickly access a Free Online Stoichiometry Calculator to help you balance any given chemical reaction — by equalizing the components of reactants and products resulting in a balanced equation. Not to mention, it also provides the chemical structures of reactants, end products, and by-products.

As an example, the above illustration shows the Gas Stoichiometry Calculator ( in action for the calculation of the chemical reaction between Iron and Oxygen (more on that later on). To use it, all you’ll need is to enter the chemical equation and the Stoichiometry Calculator will readily calculate the number of reactants and products involved in it.

Basically, the Stoichiometry Calculator also outputs the equilibrium constant Kc obtained from the balanced equation. Equally important, it also gives the rate of reaction. In addition to the chemical names of the input reactants, the actual resultant products, and the by-products. But, there is a wide range of chemical properties that it outputs as well.

Getting To Know Stoichiometric Coefficients Chemical Equation Types 

Just like we stated earlier, at the end of any given chemical reaction process, the Stoichiometry Calculator will provide the user with a wide range of chemical properties of the input reactants, the expected products, as well as the by-products. On that note, the stoichiometry coefficients are the number of moles of the reactant and the product in the chemical equation.

During a chemical reaction, the substances that react are known as reactants whereas the substances that are formed during a chemical reaction are known as products. Typically, a chemical reaction is followed by physical signs that are readily detected. Such as heat and light emission, precipitate formation, gas evolution, or a change of appearance.

If you are still interested to learn more, you can let us know in our comments section so that we can come in handy. Be that as it may, there are some topmost known types of chemical reactions that we are going to list below.




Combination Also known as Synthesis Reaction, it’s a reaction in which two or more reactants combine to form a single product. X + Y → XY (2Na + Cl2 → 2NaCl)
Decomposition Opposite of a combination reaction, it’s a reaction in which a single compound breaks into two, or rather, many simpler compounds. AB → A + B (CaCO3 → CaO + CO2)
Precipitation Two solutions of soluble salts are mixed resulting in an insoluble solid (precipitate) product formation. The reactants are soluble, but the product formed would be insoluble and separates out as a solid. A + Soluble Salt B  → Precipitate + Soluble Salt C
Neutralization An acid and a base react with each other. Generally, the product of this reaction is salt and water. Acid + Base → Salt + Water
Combustion A reaction where Oxygen combines with a compound to form Carbon Dioxide and Water. These reactions are exothermic, meaning they give off heat. A + O2 → H2O + CO2
Displacement  Also known as substitution reaction, it’s a chemical reaction in which a more reactive element displaces a less reactive element from its aqueous salt solution. D + EF → DF + E (Zn + CuSO4 → ZnSO4 + Cu)

When you are able to find the Stoichiometry Coefficient, then you can mix the molar concentration at a specific temperature and pressure. The Stoichiometric Coefficients can also be fractions or ratios. But, the whole numbers are preferred to represent the near-to-exact proportionality of the reactants and the products. Still, the law of combining proportions will also apply here.

It’s, important to realize, that the Gas Stoichiometry Calculator (showcased above) only uses the whole number to estimate the proportional ratio of the reactants and the products. In essence, it assists to avoid any kind of ambiguity and complication during the chemical reaction. Moving on, there are various types of Stoichiometry that are essential to understand.

Particularly, when it comes to balancing a chemical equation. Whilst, bearing in mind, that the Stoichiometry Calculator automatically converts the molar concentration into the atomic weight. Let’s now learn from a few examples below.

Using The Stoichiometry Calculator To Balance Chemical Equations

To begin with, let’s consider a precipitation reaction as an example equation that needs a chemical calculation solution. First, it’s worth mentioning that a precipitation reaction occurs when a mix of solution compounds, originally containing dissolved species, produces a solid product. Essentially, which generally is denser and falls to the bottom of the reaction vessel.

Secondly, the most common precipitation reactions occur in an aqueous solution — it involves the formation of an insoluble ionic compound when two solutions containing soluble compounds are mixed. With that in mind, let’s consider what happens when an aqueous solution of NaCl is added to an aqueous solution of AgNO3.

Whereby, on one side, the first solution contains hydrated Na+ and Cl− ions, and the second solution, on the other side, contains Ag+, and NO3− ions. In that case, we can try and list the main precipitation reaction compounds first.

Something like this:

NaCl(s) → Na+(aq) + Cl(aq)

AgNO3(s) → Ag+(aq) + NO3(aq)

When mixed, a double displacement reaction takes place, forming the soluble compound NaNO3 and the insoluble compound AgCl. In the reaction vessel, the Ag+ and Cl ions combine, and a white solid precipitates from the solution — where the Na+ and NO3 ions remain in the solution. The overall double displacement reaction will be in a balanced equation form:

NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq)

Example Problem:
  1. When aqueous solutions of Pb(NO3)2 and KI are mixed, does a precipitate form?
  2. Write a balanced equation for the precipitation reaction that occurs;
  3. Perse, when aqueous solutions of copper(II) iodide and potassium hydroxide are combined.

The solution is that you’ll be asked to predict whether a precipitate will form during a chemical reaction and to write a balanced equation for a precipitation reaction. And, as such, you’ll be given the identity of two reactants that answers the following.

1. Yes, a solid precipitate, PbI2, forms when these solutions are mixed:

Pb(NO3)2(aq) + KI(aq) → PbI2(s) + 2KNO3(aq)

2. The two products of the reaction are insoluble copper (II) hydroxide and soluble potassium iodide.

CuI2(aq) + 2 KOH(aq) → Cu(OH)2(s) + 2 KI(aq)

Another example is that when the molar concentration of water H2O is equal to 2, it can be converted into atomic weight.

Such as follows:
  • First, the molar concentration of water = 2H2O
  • Secondly, the atomic weight of water = 2(1)+(16)= 18 grams
  • And then, for  2 moles of water= 2(18) = 36 grams.

Moles To Moles Stoichiometry:

If in a reaction, you need to determine the Moles To Moles Stoichiometry, then follow the steps:

  1. First, convert the units of reactants and products into the corresponding number of moles.
  2. Once you calculate the moles of the reactants and the product, adjust the chemical equation
  3. There should be an equal number of moles of the reactant and the product in the balanced chemical equation

Mass To Mass Stoichiometry:

The other method of balancing a chemical equation is by balancing the masses of the reactant and the product.

  1. In the first step Write down the balanced stoichiometry of chemical equations
  2. Now Convert the reactant atomic mass into an equal number of moles
  3. Find the moles of the desired product and its atomic mass 
  4. Now finally balanced the atomic masses of the reactant and the products in the chemical equation.

You can choose the stoichiometry calculator to find the molar stichometry or the Mass To Mass Stoichiometry of the chemical equation. Whereby, as we said, you just need to enter the chemical equation in the online calculator.

Another Practical Chemical Reaction Example — Iron (Metal) + Oxygen (Air)

Suppose you are experiencing the rusting of the iron metal and the iron is reacting with the oxygen of the air to make the Iron Oxide. If we want to write down the stoichiometric equation, you’ll need to follow the simple steps written for Fe+O2=Fe2O3. Clearly, the Solution is to do the Stoichiometric Calculations as we are going to illustrate below.

Step #1:

The balanced chemical stoichiometry equation of the iron oxide formation reaction is written as


Step #2:

You need to find the atomic weight and the molecular masses for each element of the reactant and the product.

Atomic masses:
  • Iron =Fe=26
  • Oxygen =O= 16

For calculations and steps, tap the atomic mass calculator.

Molecular mass:

Fe2O3 = 2(26)+3(16) = 104

Here with the help of another molecular formula calculator, you can get to know the steps involved in calculating the molecular mass of any compound. The above information can also be displayed in the Stoichiometry table form:

Atomic Mass Molecular Mass
  • Fe=26
  • O = 16


Step #3:

Balance the chemical equation of the and it gives us the idea of the molar concentration of the reactant and the products.

4Fe+3O2 → 2Fe2O3

Step #4:

Herein, you’ll need to find the atomic masses and the molar masses of the reactant and the products. The number of moles is going to be multiplied by the atomic masses of the reactant and product. it’s now possible to find the reactant number in grams. As per the laws of the conservation of the masses, the same amount or the quality of the product is produced.

On one hand, you can use the Stoichiometry Calculator to find the chemical quality of the reactants and the products. And now, let’s sample out the resulting chemical reaction of the Iron Oxide (Fe2O3) that occurs when 4 moles of Iron (Fe) react with three moles of Oxygen (O2) — to produce 2 Moles of Iron Oxide. You can write the molar concentration in grams.

Such as follows:
  • 4 moles of the iron = 4(26) =104 grams.
  • 3moles of the Oxygen = 3(16*2) =96grams.
  • 2 moles of the Iron Oxide=Fe2O3 = 2[2(26)+3(16)] =204 grams of Fe2O3

In layman’s language, it means that 104 grams of iron are going to react with the 96 grams of Oxygen. Suffice it to say, that there would be 204 grams of Iron Oxide that are going to be produced as a result of this chemical reaction.

Frequently Asked Questions Answered

1. What is chemical reaction and equation?

A chemical equation is a symbolic representation in the form of symbols and formulas of a chemical reaction in which the reactant entities on the left-hand side and the product entities on the right-hand side are given. Still, a molecular equation may indicate formulas of reactants and products that are not present. And, as such, eliminate completely the formulas of the ions that are the real reactants and products.

2. When is there a chemical change difference?

The chemical equation by which a chemical change is described is adequate for reactions in solutions. But, for reactions of ionic compounds in an aqueous solution (water), the typical molecular equation has different representations. If the substance in the molecular equation that is actually present as dissociated ions are written in the form of their ions, the result is an ionic equation.

3. Why do we write a chemical equation?

The purpose of writing a balanced chemical equation is to explain the occurring reactants (starting material) and products (end results). The ratios in which they answer so that you can measure the number of reactants you need and the number of goods you can make.

4. How do you identify physical and chemical changes?

The shape or form of the matter varies through a physical transition, but the sort of matter in the material does not. In a chemical shift, however, the type of matter shifts, and at least one new material with new properties is created. There is no straight cut of the gap between the physical and chemical transition.

5. What is the skeleton equation?

A skeleton equation is when each product that takes part in the reaction is written with the chemical formulas describing the chemical reaction. Examples: The term equation: oxygen + methane. Dioxide with carbon + Vapour.


Generally speaking, Stoichiometry is a very important branch of Chemistry — for it deals with the relationship between chemical quantities. More so, by obtaining equilibrium in any given chemical reaction to stabilize the reaction. Whereby, the reactants chemically react together to give expected product results — there are also some end-result by-products.

Not forgetting, just as we aforementioned, the Stoichiometric Process assists you to find the molar masses of the reactant and the product in a chemical reaction. When you are able to balance the molar masses, you can get the atomic masses of the reactants and the products. In the above example, you have observed the reactant react in a given proportionality.

Resource References From:
  1. Wikipedia: Stoichiometry, Etymology, Converting grams to moles, molar proportion, Determining amount of product, Stoichiometric ratio, Limiting reagent and percent yield, Stoichiometry matrix
  2. Khan Academy: Balancing chemical equations, Calculating amounts of reactants and products, ideal stoichiometry
  3. Lumen Learning: Reaction Stoichiometry, moles to moles, Grams to Moles

That’s our wrap! If you think that there is something else that you think it’s worth adding or mentioning in this guide, kindly Contact Us and let us know. You are also welcome to share your additional thoughts, opinions, suggestions, recommendations, or even contribution questions for Free FAQ Answers in our comments section. Thanks for your time, you are welcome!

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