Reacting Masses and the Limiting Reactant
Pick a balanced reaction and the amount of each reactant, and watch particles pair up in the equation's ratio until one reactant runs out. See the limiting reactant, the mass or gas volume of product made, and the excess left behind, and why moles, not grams, decide which runs out first.
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What you can adjust
- Reaction
- 0 – 5
- Mass of the first reactant
- 0.1 – 50 g
- Mass of the second reactant (sulfur or oxygen)
- 0.1 – 50 g
- Volume of the second reactant's solution
- 10 – 250 cm³
- Concentration of that solution
- 0.1 – 2 mol/dm³
- Percentage yield
- 50 – 100 %
Six balanced reactions. The numbers in front of the formulas (the coefficients) say how many moles of each substance take part, and they decide which reactant runs out first.
The mass of the first substance on the left of the equation, in grams. Its moles are the mass divided by its relative formula mass.
Used only for the two reactions where the second reactant is a solid or a gas (Fe + S and 2H₂ + O₂). For the other four, the second reactant is a solution and this slider is ignored.
Used only when the second reactant is a solution (HCl, CuSO₄ or NaCl). Moles = concentration × volume in dm³ (divide cm³ by 1000). Ignored for Fe + S and 2H₂ + O₂.
Moles of the dissolved substance in each dm³ of solution. Used only when the second reactant is a solution. Ignored for Fe + S and 2H₂ + O₂.
How much of the possible product is actually made. 100 % means every mole of the limiting reactant reacts. Lower values leave some of both reactants unreacted.