Unit 4, Lesson 24

One can remove harmful substances from a water source by precipitating harmful ions from it. How does one do that, exactly? It's more of a question of how much of two reactants are needed to achieve a solid precipitate, and to answer that question, mole ratios come into play. The ratios can be identified by coefficients, the big numbers before compounds in a chemical equations. Those coefficients tell you how many moles of a certain substance are present in a reaction. They can be read by "for every __ mole(s) of reactant 1, there are __ mole(s) of reactant 2." You can also say "for every __ mole(s) of reactant one (or 2), there are __ mole(s) of product one (or two)." Sometimes we aren't given equal amounts of reactants in a reaction. In this case, one runs out first, and that reactant is called the limiting reactant. The one left over is the excess reactant.

Practice Poblems:

A convenient photo has appeared!