Molar Mass

{
  "asOf": "2026-10-11T08:45:39.976Z",
  "composition": [
    {
      "atomicWeight": 12.011,
      "atoms": 6,
      "element": "C",
      "massGramsPerMole": 72.066,
      "massPercent": 40.002,
      "name": "Carbon"
    },
    {
      "atomicWeight": 1.008,
      "atoms": 12,
      "element": "H",
      "massGramsPerMole": 12.096,
      "massPercent": 6.71418,
      "name": "Hydrogen"
    }
  ],
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "hillFormula": "C6H12O6",
  "input": "C6H12O6",
  "molarMassGPerMol": 180.156,
  "notChecked": [
    "whether the formula is a real compound",
    "isotopic composition (standard atomic weights are used)",
    "…2 more"
  ],
  "reasons": [
    "Sum of IUPAC standard atomic weights times atom counts (abridged values, about 4 significant figures for most elements).",
    "All elements have a standard atomic weight."
  ],
  "source": "computed locally",
  "summary": "C6H12O6 (C6H12O6): 180.156 g/mol; C 40%, H 6.714%, O 53.28%.",
  "totalAtoms": 24,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://chemistry-calc.x402tookit.com/molar-mass?formula=C6H12O6'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://chemistry-calc.x402tookit.com/molar-mass?formula=C6H12O6' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fchemistry-calc.x402tookit.com%2Fmolar-mass
const res = await pay("https://chemistry-calc.x402tookit.com/molar-mass?formula=C6H12O6");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://chemistry-calc.x402tookit.com/molar-mass?formula=C6H12O6")
    print(res.status_code, res.text)