Cambridge IGCSE Chemistry · Syllabus 0620 · Stoichiometry
Reacting mass
What is Reacting mass?
A reacting mass is the mass of one substance that takes part in or is formed by a chemical reaction, worked out from the fixed proportion that a balanced equation sets between the substances; that proportion is found by multiplying each substance's relative atomic, molecular or formula mass by its coefficient in the equation, and any real quantity is then reached by scaling the whole proportion by a single factor.
This definition is part of the Stoichiometry chapter in Cambridge IGCSE Chemistry.