Theoretical yield from limiting reactant calculator
Two moles of hydrogen limiting the water synthesis give at most 36 g of water. Enter the limiting moles, both coefficients and the product's molar mass to get the mole ratio, the product moles and the theoretical yield as a mass. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Limiting moles
- 2
- Limiting coeff
- 2
- Product coeff
- 2
- Product molar mass
- 18
- Mole ratio
- 1
- Product moles
- 2
- Theoretical yield
- 36
- Precision
- 10
This theoretical yield from limiting reactant calculator turns the moles of a known limiting reagent into the maximum product mass a balanced reaction can produce. You supply the moles of the limiting reactant, the stoichiometric coefficient of that reactant, the stoichiometric coefficient of the product, and the product molar mass. The engine forms the mole ratio as product coefficient over limiting coefficient, multiplies by the limiting moles to get product moles, then multiplies by the product molar mass to report theoretical yield. Classic classroom checks include two moles of hydrogen limiting in the water synthesis with coefficients two and two and molar mass eighteen, which yields thirty-six mass units of water, and one mole of nitrogen limiting in ammonia synthesis with coefficients one and two and molar mass seventeen, which yields thirty-four mass units of ammonia. The engine uses only finite deterministic arithmetic with no network calls, no sampling, and no date-dependent shortcuts.
What the theoretical yield tells you
Theoretical yield is the maximum mass of product that can form when the limiting reactant is fully consumed under ideal conditions with a balanced chemical equation. After you already know which species limits the reaction and how many moles of it are available, the stoichiometric coefficients fix the mole ratio between that reactant and the product of interest. Multiplying limiting moles by product coefficient over limiting coefficient produces the moles of product expected; multiplying those product moles by the product molar mass produces the theoretical yield as a mass.
Zero moles of limiting reactant with valid positive partners is allowed and yields zero product mass, which is the correct ideal limit when no limiting material is present.
Where theoretical-yield calculation fits in study, lab work, and software
Students meet theoretical-yield problems when a textbook introduces limiting reactants after balancing equations, when a homework set already states which reagent limits and asks for the maximum product mass, or when a contest problem expects a clear numeric yield before any percent-yield step. Teachers can pre-generate answer keys for modest molar masses and integer coefficients without trusting opaque apps that mix percent yield with limiting analysis or assume wrong units.
Lab technicians and preparers use the same closed form when a protocol already measured moles of the limiting starting material and only the balanced coefficients and product molar mass remain: multiply by the mole ratio, convert with molar mass, and plan how much product is ideally available. Developers call the same contract from scripts to seed deterministic test vectors for chemistry tutors, to normalize user-entered reaction parameters before a lab notebook export, or to satisfy programming-challenge statements that demand a theoretical mass rather than a hand-waved sketch.
What you can do with it
Homework and theoretical-yield checks
Convert known limiting moles and balanced coefficients into theoretical product mass using product molar mass before grading or percent-yield work.
Lab prep and education software
Compute ideal product mass from measured limiting moles in lab notebooks, tutoring UIs, and automated worksheet generators.
FAQ
What does the theoretical yield from limiting reactant calculator cost?
It is free in your browser on this page.
Does this tool identify the limiting reactant or compute percent yield?
No. You must already know the limiting moles. It only returns theoretical product mass. Use a limiting-reactant or percent-yield calculator for those steps.
Why are results rounded to a precision?
Default precision is 10 decimal places; you can set precision from 0 to 15.
Which molar mass do I enter?
The molar mass of the product you are making, usually in g/mol. The yield comes out in the matching mass unit, so water at 18 g/mol from two limiting moles of hydrogen gives 36 g.
How much ammonia can one mole of nitrogen produce?
At most 34 g. With coefficients one for nitrogen and two for ammonia, one mole of nitrogen makes two moles of ammonia, and two moles at 17 g/mol give 34 g.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/chem/theoretical-yield-from-limiting \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"limiting_moles":2,"limiting_coeff":2,"product_coeff":2,"product_molar_mass":18}'const res = await fetch("https://api.kit.forhosting.com/chem/theoretical-yield-from-limiting", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"limiting_moles": 2,
"limiting_coeff": 2,
"product_coeff": 2,
"product_molar_mass": 18
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/chem/theoretical-yield-from-limiting",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"limiting_moles": 2,
"limiting_coeff": 2,
"product_coeff": 2,
"product_molar_mass": 18
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/theoretical-yield-from-limiting", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"limiting_moles":2,"limiting_coeff":2,"product_coeff":2,"product_molar_mass":18}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"limiting_moles":2,"limiting_coeff":2,"product_coeff":2,"product_molar_mass":18}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/theoretical-yield-from-limiting", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"limiting_moles": 2,
"limiting_coeff": 2,
"product_coeff": 2,
"product_molar_mass": 18
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "chem.theoretical_yield_from_limiting",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_abs_value | 1000000000000000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
What theoretical yield means and what the response contains
This calculator returns the validated limiting_moles, limiting_coeff, product_coeff, and product_molar_mass, the derived mole_ratio, product_moles, and theoretical_yield, the precision used, a method tag theoretical_yield_from_limiting, and a short formula reminder. There is no mass-to-moles conversion for the reactant, no percent-yield path, no multi-product search, and no equation balancer: the engine either applies the closed form inside the supported numeric range or rejects the input with invalid_input. Rejected cases include missing required fields, non-finite values, magnitudes above the documented ceiling, negative limiting moles, any stoichiometric coefficient that is zero, and any product molar mass that is zero or negative, because a zero coefficient makes the mole ratio undefined or non-physical and a non-positive molar mass cannot convert product moles into a mass yield.
How moles, coefficients, and molar mass are read and stay reproducible
Optional leading plus signs and scientific notation on numeric strings are allowed when they parse as finite decimals; embedded spaces and non-numeric tokens are rejected. The preferred field for the moles of the limiting reactant is limiting_moles, but aliases n_limiting, moles_limiting, n_lim, and limitingMoles are accepted so spreadsheets, query strings, and typed forms can reuse the same contract. The stoichiometric coefficient of the limiting reactant uses limiting_coeff with aliases coeff_limiting, a, n_a, and coeff_lim. The product coefficient uses product_coeff with aliases coeff_product, b, n_b, and coeff_prod. Both coefficients must be finite and non-zero; a zero coefficient fails with invalid_input and a message that names the field so a bad cell does not become a silent division by zero. Product molar mass uses product_molar_mass with aliases mm_product, product_mm, M_product, and productMolarMass, and must be a strictly positive finite number in grams per mole or any mass-per-mole unit consistent with the yield mass you want reported. An optional precision field, with aliases decimals and dp, chooses how many decimal places to expose for the numeric outputs, defaulting to ten and capped at fifteen so JSON goldens stay stable. Computation forms mole_ratio equals product_coeff over limiting_coeff, product_moles equals limiting_moles times mole_ratio, and theoretical_yield equals product_moles times product_molar_mass. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing the mole-ratio multiplication yourself.
Where theoretical-yield calculation fits in study, lab work, and software
Product and education tools use the endpoint when a learner types limiting moles, two coefficients, and a product molar mass and the UI must show theoretical_yield with clear intermediate mole_ratio and product_moles. On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the mathematical result. Pair it with limiting-reactant or mass-to-mass helpers when you need related chemistry quantities, and with other science endpoints when you are building a small lab of free, deterministic stoichiometry calculators.
Integration use cases
Deterministic test fixtures
Generate reproducible theoretical_yield, product_moles, and mole_ratio for unit tests, chemistry tutors, and CI assertions on limiting-based yield.
Technical questions
How is theoretical yield computed?
mole_ratio = product_coeff / limiting_coeff, product_moles = limiting_moles × mole_ratio, and theoretical_yield = product_moles × product_molar_mass.
What happens if a coefficient is zero?
The input is rejected with invalid_input. A zero limiting_coeff makes the mole ratio undefined (division by zero), and a zero product_coeff is treated as non-physical for theoretical yield.