Final answer:
A balanced chemical equation has the same number of each type of atom on both the reactant and the product sides. Examples of balanced reactions provided include 2Hg + O2 → Hg2O2, C2H4 + 2O2 → 2CO2 + 2H2O, and Mg(NO3)2 + 2Li → Mg + 2LiNO3, illustrating stoichiometry principles.
Step-by-step explanation:
To determine a balanced chemical equation, one must ensure that the number of atoms of each element is the same on both the reactant and the product sides. For example, considering the reaction a b → 2c, we would need more information to balance the equation correctly. However, based on the provided sample reactions, we can analyze their balance.
The reaction 2Hg(e) + O2(g) → Hg2O2(s) appears to be balanced, as there are two mercury atoms and two oxygen atoms on both sides. The reaction C2H4(g) + 2O2(g) → 2CO2(g) + 2H2O(l) is also balanced, with the correct number of carbon, hydrogen, and oxygen atoms on both sides. Lastly, the reaction Mg(NO3)2(s) + 2Li(s) → Mg(s) + 2LiNO3(s) is balanced with one magnesium atom, two nitrogen atoms, and six oxygen atoms on both sides.
Stoichiometry and the conservation of mass principle are both fundamental in ensuring a reaction is balanced, with stoichiometry providing the quantitative relationship between the reactants and products in a chemical reaction.