Limiting ReactantIdentifying which reactant runs out first.ChemistryThe reliable method.1Convert every reactant to molesFrom mass, volume or concentration.2Divide each by its coefficientFrom the balanced equation.3The smallest value is limitingThat reactant runs out first.4Use it for every product calculationThe excess is irrelevant to the yield.EXAMPLE2H₂ + O₂ → 2H₂O4 mol H₂ ÷ 2 = 23 mol O₂ ÷ 1 = 3Hydrogen is limiting; 4 mol of water formsComparing raw moles without dividing by the coefficients gives thewrong answer whenever the ratio is not 1:1.Limiting Reactantlearnposters.com
Limiting Reactant — printable physical science wall chart from LearnPosters. Free vector PDF, US Letter and A4.

Limiting Reactant, step by step

The reliable method.

  1. Convert every reactant to molesFrom mass, volume or concentration.
  2. Divide each by its coefficientFrom the balanced equation.
  3. The smallest value is limitingThat reactant runs out first.
  4. Use it for every product calculationThe excess is irrelevant to the yield.

Example

  • 2H₂ + O₂ → 2H₂O
  • 4 mol H₂ ÷ 2 = 2
  • 3 mol O₂ ÷ 1 = 3
  • Hydrogen is limiting; 4 mol of water forms

Comparing raw moles without dividing by the coefficients gives the wrong answer whenever the ratio is not 1:1.

Questions about the Limiting Reactant poster

What’s on the Limiting Reactant poster?
4 numbered steps, with a full worked run-through. The reliable method. Convert every reactant to moles — From mass, volume or concentration.; Divide each by its coefficient — From the balanced equation.; The smallest value is limiting — That reactant runs out first.; Use it for every product calculation — The excess is irrelevant to the yield.. Comparing raw moles without dividing by the coefficients gives the wrong answer whenever the ratio is not 1:1.
Who is the Limiting Reactant poster for?
Limiting Reactant belongs to the Chemistry section rather than to a school year, because physical science is not something one grade owns. Anyone learning calculations can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Limiting Reactant poster?
Divide moles by the coefficient. The smallest result is limiting. A wall chart earns its place by being glanceable from where the work is happening, so Limiting Reactant belongs on the wall where that physical science work actually happens, within glancing distance, rather than filed away.
What other posters go with Limiting Reactant?
Percentage Yield, Atom Economy and Formula Summary sit alongside Limiting Reactant in the Chemistry section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Percentage YieldAtom EconomyFormula Summary
Is the Limiting Reactant poster free to download and print?
Yes. Limiting Reactant downloads as a free PDF with no account, no email and no watermark, like everything else in the Chemistry section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Limiting Reactant poster print at?
Limiting Reactant is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Limiting Reactant loses nothing.Printing guide

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