Student Exploration: Limiting Reactants
Vocabulary: chemical equation, chemical formula, chemical reaction, coefficient, limiting reactant, molecule, product, reactant, subscript
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
Imagine you and your friends are making hot dogs. A complete hot dog consists of a wiener and a bun. At the store, you buy four packages of eight wieners and three bags of 10 buns.
How many total hot dogs can you make? ______________________________________
Which ingredient limited the number of hot dogs you could make? __ ____________
Which ingredient will you have leftovers of? ____________________ _________
Just as ingredients can be put together to make a new food, substances can combine during a chemical reaction to produce new substances. The substances that undergo change are called reactants. The new substances are products.
Sometimes during a chemical reaction, one type of reactant will be used up before the other reactants. This reactant is the limiting reactant. Using the Limiting Reactants Gizmo™, you can determine which reactant is limiting in various scenarios.
To begin, make sure H2 + O2 becomes H2O is selected. The small “2” in H2, O2, and H2O is a subscript. Subscripts represent the number of atoms in a molecule.
Use the sliders to set the number of O2 molecules and H2 molecules to two.
How many hydrogen molecules (H2) are there? _______ Hydrogen atoms? _______
How many oxygen molecules (O2) are there? _______ Oxygen atoms? ___
How many H2O molecules do you think will form when these four molecules react? ______
Click Play (). How many H2O molecules actually formed? _____