ForHosting KIT · Developer Utilities

Grams of solute for molarity calculator

This grams-of-solute-for-molarity calculator tells you how many grams of pure solid or pure liquid solute you need to weigh out when you want a solution of a stated molar concentration.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

You supply the target molarity in moles per litre, the final solution volume in litres, and the solute molar mass in grams per mole; the engine multiplies them with the closed form grams equals M times V times MM, which is the same as computing moles first and then converting moles to mass. Classic lab checks include half-molar sodium chloride in a quarter litre with MM of 58.44 grams per mole, which needs 0.125 moles and 7.305 grams, and one-molar sodium hydroxide in one litre with MM of 40, which needs exactly 40 grams. Everything runs with finite deterministic arithmetic only: no network calls, no random sampling, and no date-dependent behaviour. Use the free browser tool for lab prep, homework, and buffer recipes, or call the API at $0.002 per successful request when teaching software, LIMS scripts, or CI fixtures need the same mass answer every time.

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

POSThttps://api.kit.forhosting.com/chem/grams-solute-for-molarity

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/grams-solute-for-molarity \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"molarity":0.5,"volume":0.25,"molar_mass":58.44}'

const res = await fetch("https://api.kit.forhosting.com/chem/grams-solute-for-molarity", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "molarity": 0.5,
    "volume": 0.25,
    "molar_mass": 58.44
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/chem/grams-solute-for-molarity",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "molarity": 0.5,
    "volume": 0.25,
    "molar_mass": 58.44
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/grams-solute-for-molarity", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"molarity":0.5,"volume":0.25,"molar_mass":58.44}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"molarity":0.5,"volume":0.25,"molar_mass":58.44}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/grams-solute-for-molarity", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "molarity": 0.5,
  "volume": 0.25,
  "molar_mass": 58.44
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "chem.grams_solute_for_molarity",
  "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

Per request$0.002

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.

Read the full KIT documentation →

Run — free