Hello!
1) Stoichiometry comes from the Greek <span>stoikheion "
Element" and </span><span>métrón "
Measure". It is the calculation of the
quantitative relationships between reagents an products in a chemical reaction. The foundation of stoichiometry is the
Law of Conservation of Mass. The relation between reagents and products can be estimated from the atomic theory and were first enunciated by
Jeremias Benjamin Ritcher.2) A. Mole Ratios are the relation between two elements or compounds in a chemical reaction and arise from the coefficients in a balanced chemical equation. For the reaction
2HgO(s) </span>
→ 2Hg(l) + O₂(g)The possible mole ratios are:
2) B. Mole Ratios are the relation between two elements or compounds in a chemical reaction and arise from the coefficients in a balanced chemical equation. For the reaction:
4NH₃(g) + 6NO(g) → 5N₂(g) + 6H₂O(l)
The possible mole ratios are:
3) In stoichiometry, the
mole ratio is crucial for the calculations because it is the quantity that allows us to
convert the moles of an element or compound into the moles of another element or compound. Once we know the moles of a substance in the chemical reaction using the molar mass, if we want to know the moles of another substance we need to use the mole ratios.
4) Before solving any stoichiometry problem we need to
balance the chemical equation for the given reaction. Balancing a chemical equation allows us to be sure that the
Law of Conservation of Mass is fulfilled, and that any calculation or conclusion derived from the reaction is truthful. If the balancing is wrong, all mole ratios and calculations will be wrong too, as everything depends on the proper balancing of the chemical equation.
Have a nice day!