Simulation · Chemistry · Class 11
Which reactant runs out first?
From the lesson Stoichiometry and the limiting reagent in Some Basic Concepts of Chemistry. Change the values and watch what happens.
The idea behind it
NCERT § "Stoichiometry and Stoichiometric Calculations"
- Stoichiometry is the calculation of the masses and, for gases, volumes of reactants and products from a balanced equation.
- The coefficients in a balanced equation give mole ratios (and, for gases at the same temperature and pressure, volume ratios), not mass ratios.
- Balancing an equation means making the count of every element match on the left and right sides; this is conservation of mass written in symbols.
- The limiting reagent is the reactant that is used up first; it alone decides how much product forms, and the other reactant is left in excess.
- To find it, divide the available moles of each reactant by its coefficient; the smallest quotient marks the limiting reagent.
- When a sample is impure, first find the mass of the pure reacting substance from its percentage purity, then do the mole calculation.