Molar mass from formula API

Parses a chemical formula (nested parentheses, brackets, hydrate dots) and returns molar mass with a per-element mass breakdown and percent composition, using an audited inline atomic-weight table. Answers 'What is the molar mass of C6H12O6?', 'What percent of glucose is carbon?'.

Price$0.04per request

MethodPOST

Route/v1/chemistry/molar-mass

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

chemistrymolar-massmolecular-weightformulastoichiometrypercent-compositionatomic-masschemical

API URLhttps://x402.hexl.dev/v1/chemistry/molar-mass

Integration docs

Example request

{
  "formula": "C6H12O6"
}

Example response

{
  "formula": "C6H12O6",
  "molarMass": 180.156,
  "units": "g/mol",
  "atomCount": 24,
  "composition": {
    "C": 6,
    "H": 12,
    "O": 6
  },
  "breakdown": [
    {
      "element": "C",
      "atomicMass": 12.011,
      "count": 6,
      "mass": 72.066,
      "massPercent": 40.002
    },
    {
      "element": "H",
      "atomicMass": 1.008,
      "count": 12,
      "mass": 12.096,
      "massPercent": 6.7142
    },
    {
      "element": "O",
      "atomicMass": 15.999,
      "count": 6,
      "mass": 95.994,
      "massPercent": 53.2838
    }
  ]
}

Input schema

{
  "type": "object",
  "required": [
    "formula"
  ],
  "properties": {
    "formula": {
      "type": "string",
      "description": "Chemical formula, e.g. C6H12O6, Fe2(SO4)3, CuSO4·5H2O",
      "examples": [
        "C6H12O6",
        "Fe2(SO4)3",
        "CuSO4·5H2O"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}