Stoichiometry Problem Solver, Calculate and Convert Grams -> Moles -> Moles -> Grams

In the world of chemistry, stoichiometry can be a time-consuming and sometimes confusing unit to study.  To help with your stoichiometry homework, here’s a brief overview of the topic and some links to useful and free calculators and problem solving programs.

What is Stoichiometry?

In a nutshell, it’s the process of determining how much input you need or output you’ll get for a given amount or quantity.  In other words, it’s like working with any recipe in the kitchen.  You need to be able to:

  1. convert between units (volume, mass, moles, sometimes atoms/molecules/particles)
  2. scale the chemical formula/equation (recipe) up or down

A few general rules of thumb include:

  • convert moles to grams and grams to moles for a given molecule/substance/compound using its molar mass (also referred to as molar weight)
  • convert molecules to moles (particles to moles) and vice versa using Avogadro’s number, 6.02 x 1023
  • you can only convert between amount of input to output and vice versa with a BALANCED chemical equation.


Double check your stoichiometry homework with these problem solvers for chemistry!  Find number of moles for a given mass of substance, grams for a given number of moles, moles or grams of product given moles or grams of reactant.

  • Ucrecia

    cool cooooooooooool

  • Nick007

    save rain forests! donate to world land trust

  • ChemSucksDick

    I hate chemistry so bad man even tho I somehow managed to get a B every quarter idk thank u for the homework otherwise Id have like a D

  • Bloodlyneck

    tell me about i’m taking it now it is not fun

  • flaminius

    I would never have made oit through any chemistry cvalss without various “engines” available either free or for 60 or 100 bucks which can do the “scut” work . Once you see how the damn calculator-computer does it, it is very easy to do it yourself. A half decent calculator is the real necessity.

  • montell

    Can some one help me out with this mass to mass problem Sb2O3+3C=2Sb+3CO

  • hals

    can anyone help with this problem? Aluminum reacts with chlorine to form aluminum chloride if 17.56 grams of aluminum reacts with excess chlorine, what mass of aluminum chloride is produced?

  • creighton goffney

    how many moles of calcium hydroxide are generated when 6.0 moles of aluminum hydroxide react with excess calcium chloride?

  • chris

    please i nedd help
    how many moles of O2 are produced from 7.19 mol of Al2O3

  • Samantha Burns

    what volume of hydrogen will be produced at stp by the reaction of 78.33 g of aluminium with excess water ?
    Here’s the equation : 2Al+6H2O–>2Al(OH)3+3H
    Whoever can solve this , thank you , you’re amazing