Avogadro's law moles calculator
This Avogadro's law moles calculator finds the final amount of gas when volume changes at constant temperature and pressure.
Run — free
You supply the initial volume V1, the final volume V2, and the initial moles n1; the engine returns the final moles n2 from the classical proportion V1 over n1 equals V2 over n2, which rearranges to n2 equals n1 times V2 over V1. That identity is the gas-phase form of Avogadro's principle: equal volumes of ideal gas at the same T and P contain equal numbers of particles, so moles scale linearly with volume when those conditions hold. Worked checks include V1 equals two, V2 equals four, n1 equals one yielding n2 equals two, and V1 equals five, V2 equals two point five, n1 equals zero point eight yielding n2 equals zero point four. The path is pure finite arithmetic with no network calls, no sampling, and no date-dependent shortcuts. Use it free in the browser for homework, lab prep, and stoichiometry drills, or call the API at $0.002 per successful request when you need reproducible mole-change fixtures in CI, tutoring software, or teaching demos.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
How do I use this capability?
Complete the fields above and run it on this page. The form highlights anything that needs attention.
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/avogadro-law-moles \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"V1":2,"V2":4,"n1":1}'const res = await fetch("https://api.kit.forhosting.com/chem/avogadro-law-moles", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"V1": 2,
"V2": 4,
"n1": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/chem/avogadro-law-moles",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"V1": 2,
"V2": 4,
"n1": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/avogadro-law-moles", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"V1":2,"V2":4,"n1":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"V1":2,"V2":4,"n1":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/avogadro-law-moles", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"V1": 2,
"V2": 4,
"n1": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "chem.avogadro_law_moles",
"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. |