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Practice Problems

Stoichiometry Calculator

Stoichiometry Calculator
Input Gas Type

Real Gas Parameters
Mass Volume Pressure

Moles: Molar Mass:
Mass: Molarity:
Volume: Density:


Retrieve the molar mass of a compound from its chemical formula and convert between mass, volume, pressure, molarity, density, and number of moles. The stoichiometry calculator will calculate all non-arbitrary physical values from any given initial values. For example, inputting H2O for the compound and 2 for the number of moles will give the molar mass of water and the amount of grams contained in 2mol. If a volume is given, the calculator will also be able to calculate the molarity, pressure (assuming the compound is a gas), and density. Gases can be calculated as ideal gases, van der Waals real gases, or Redlich-Kwong real gases.

* For scientific notation, use Ex to represent 10x (e.g. 1.7x105 would be input as 1.7E5).
* Check your input; inaccurate input value (e.g. nonexist element or unclosed parenthesis) my cause unexpected results.
* Make sure to give values for all required inputs (e.g. if you are inputting a compound's partial pressure, you must also give the system's temperature and volume).
* For reaction stoichiometry, use the Reaction Stoichiometry Calculator.
* For stoichiometry practice problems, visit the Practice Problems section.


  1. Enter a compound into the Compound box.
  2. If measuring a real gas, select the gas type.
  3. Enter all known parameters into the remaining boxes. If a value is unknown, leave the value as 0.
  4. Select the units of measurement being used.
  5. Hit Calculate to calculate any remaining data from the input data.