Question

Stoichiometry is best defined as the

Answer 1

Stoichiometry is “quantitative relationship” among the “reactants” and the “products” in a “chemical reaction”.

Step-by-step explanation:

In stoichiometry “stoicheion” means element and “metron” means measure in Greek. The stoichiometric calculation depends upon “stoichiometric coefficients” in a “chemical equation” which can be explained as the “number of moles” of each substance (reactants or products). Stoichiometric calculation is done as follows:

For example reaction between nitrogen and hydrogen to form ammonia as

`\mathrm{N}_(2)(\mathrm{g})+3 \mathrm{H}_(2)(\mathrm{g}) \longrightarrow 2 \mathrm{NH}_(3)(\mathrm{g})`

Here stoichiometric coefficients show that “one molecule of nitrogen” reacts with “three molecules of hydrogen” to form “two molecules of ammonia”. Multiplying Avogadro number
`6.022 * 10^(23)` to no of molecules in equation:

`\text { For } \mathrm{N}_(2): 1 * 6.022 * 10^(23)=1 \mathrm{mol}`

`\text { For } 3 \mathrm{H}_(2): 3 * 6.022 * 10^(23)=3 \mathrm{mol}`

`\text { For } 2 \mathrm{NH}_(3): 2 * 6.022 * 10^(23)=2 \mathrm{mol}`

Taking molar masses into consideration:

`\text { For } \mathrm{N}_(2): 1 * 28.0=28.0 \mathrm{gm}`

`\text { For } 3 \mathrm{H}_(2): 3 * 2=6.0 \mathrm{gm}`

`\text { For } 2 \mathrm{NH}_(3): 2 * 17=34 \mathrm{gm}`

Hence balanced equation gives stoichiometric coefficients which gives proportion by moles.