Stoichiometry Pro vs Stoichiometric equations
Price, ratings, monetisation and update history for both apps, side by side β with what reviewers say about each.
Stoichiometry Pro
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Stoichiometry Pro targets common stoichiometric tasks: balancing chemical reactions of unlimited number of components, finding molar masses, moles and masses of reactants and products and defining the limiting reagent, based on chemical formulas, stoichiometric coefficients, and any quantitative data provided. The app analyses chemical reaction typed in βReactionβ field, balances it (if possible), finds molar masses and builds table with list of compounds (reagents and products coloured differently), for quantitative data input. All that triggered by pressing the = button. Example 1: How many moles of H3PO4 are needed in order to obtain 2.0 g of NH4NO3, in the reaction: H3PO4 + (NH4)2MoO4 + HNO3 = (NH4)3PO4(MoO3)12 + NH4NO3 + H2O Solution: The first step is balancing chemical reaction and finding molar masses, since moles-mass conversion is needed. Reaction is balanced and all molar masses are calculated automatically by pressing the β=β button. H3PO4 + 12(NH4)2MoO4 + 21HNO3 = (NH4)3PO4(MoO3)12 +21NH4NO3 + 12H2O, The next step is to find the moles of NH4NO3 from the mass (2.0 g), and then convert them to moles of H3PO4 based on 1:21 ratio obtained from the balanced reaction. Stoichiometry application provides data table that comprised of masses and mole rows for data available before reaction initiated and obtained or left after the reaction is accomplished. When calculate button that pointing towards products, βΆβΆ is pressed, the final masses and moles are calculated from the initially provided amounts of reactant and products. On the opposite, when the calculate button pointing left,ββ, is pressed, then initial reactant and product amounts that would be required to achieve the provided final state are calculated. The later is exactly matches our situation, as we need to find the initial amount of H3PO4 from the final, known NH4NO3 mass. So we set the NH4NO3 mass (2.0 g) to the final mass field and press calculate button ββ to automatically fill the table with all masses and moles for all components. Apparently, 1.19 mmoles of H3PO4 are required to get 2.0 g of NH4NO3. Important Points: Either moles or masses can be filled in, but if both are provided and they donβt match, then the moles value will have a preference. For balancing redox reactions please refer to Electrochemistry application.
Stoichiometric equations
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Stoichiometric Equation balances chemical reaction equations for you β no trial and error, no guessing. Enter the reactants and the products, tap Balance equation, and the app returns the stoichiometric coefficients as the smallest set of whole numbers. Balancing an equation means making sure that the same number of atoms of every element appears on both sides. For a reaction such as 2Na + Clβ = 2NaCl you can still do that in your head. For e.g 3AsβSβ + 28HNOβ + 4HβO = 6HβAsOβ + 9HβSOβ + 28NO, trial and error quickly stops being practical. That is exactly where this app takes over. HOW IT WORKS Instead of guessing, the app treats the equation the way a mathematician would: every unknown coefficient becomes a variable, the atom counts for each element become one linear equation, and the resulting system is solved with Gaussian elimination. The coefficient matrix is transformed into reduced row echelon form and the solution is scaled to the smallest whole-number coefficients. The complete derivation is included in the app, step by step, with a fully worked example β so you can not only get the answer, but also understand how it is found. FEATURES β’ Balances simple reactions and long, complex equations alike β’ Nested grouping with parentheses ( ), square brackets [ ] and braces { } β’ More than 90 chemical elements, written with the international IUPAC symbols β’ Results in the smallest whole-number coefficients β’ Clear, formatted output: proper subscripts, highlighted coefficients, monospaced layout β’ Long results are wrapped automatically to fit your screen β’ Precise error messages β unbalanced brackets, unknown element symbol, non-balanceable equation and more, each named instead of a vague "invalid input" β’ A collection of ready-made example equations: tap one and it is solved instantly β’ Built-in theory section explaining the mathematics behind the solver β’ German and English interface, chosen automatically from your device language β’ Optimised for iPhone and iPad, in portrait and landscape BUILT-IN EXAMPLES The app ships with examples ranging from textbook reactions to equations that would take a very long time by hand,
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Verdict
The clearest difference is price: Stoichiometric equations at Free against Stoichiometry Pro's $3.99. Stoichiometric equations also leads on device support (4 vs 2) and iOS requirement (15.0 vs 17.0). On update cadence, ads and in-app purchases there is nothing between them.
Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS
Stoichiometric equations is free to download; Stoichiometry Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Stoichiometry Pro ships an update every 4 months, Stoichiometric equations every 3 months. The most recent releases landed on November 3, 2026 and November 8, 2026 respectively.
| Parameter | Stoichiometry Pro | Stoichiometric equations |
|---|---|---|
| Price | $3.99 | Free β better |
| Update frequency | Every 4 months | Every 3 months β better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad | iPhone, iPad, iPod, Mac β better |
| Requires iOS | 17.0 | 15.0 β better |
| Further details β not scored | ||
| Size | 2 MB | 17 MB |
| Age rating | 4+ | 9+ |
| Developer | Roman Volinsky | Peter Sauer |
In-app purchases
Stoichiometry Pro
No in-app purchases
Stoichiometric equations
No in-app purchases
Questions
Is Stoichiometry Pro free?
Is Stoichiometric equations free?
Do Stoichiometry Pro or Stoichiometric equations have ads?
Which is updated more often, Stoichiometry Pro or Stoichiometric equations?
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