Chemistry · Ch 1 — Basic Concepts of Chemistry and Chemical Calculations
Stoichiometry
Stoichiometry
The word stoichiometry comes from the Greek stoicheion (element) and metron (measure) -- it is the numerical relationship between the quantities of the substances that appear in a balanced chemical equation. Using stoichiometry, you can calculate the amount of reactant needed to make a specific amount of product, or vice versa.
The idea is introduced through an everyday cooking analogy: a kesari recipe for 6 cups of kesari calls for 1 cup rava + 2 cups sugar + ½ cup ghee + ¼ cup nuts and dry fruits. Just as you can scale this recipe up or down proportionally (e.g. working out that 3 cups of rava, kept in the same ratio, would make 18 cups of kesari), a balanced chemical equation lets you scale reactant and product amounts up or down in exactly the same proportional way. …
Worked out. An illustrated cooking analogy: the recipe for 6 cups of kesari needs 1 cup rava, 2 cups sugar, ½ cup ghee and ¼ cup nuts and dry fruits (shown as labelled bowls, with '6 cups of Kesari' assembled at the bottom from six smaller bowls). The text then shows the recipe scaled to 3 cups of kesari (working from the 6-cup ratio) and, going the other way, scaled up to the kesari obtainable from 3 cups of rava (18 cups) -- the same kind of ratio-scaling used later …