Final answer:
The given chemical reactions are classified as combination, double displacement, single displacement, and decomposition reactions. Balancing chemical equations requires adjusting coefficients to maintain equal numbers of each type of atom on both sides of the equation.
Step-by-step explanation:
Classifying the given chemical reactions is essential to understanding the type of chemical processes they represent. The first reaction, S + O₂ → SO₂, is a combination reaction where sulfur combines with oxygen to form sulfur dioxide. The second reaction, CaCl₂ + 2AgNO₃ → Ca(NO₃)₂ + 2AgCl, is an example of adouble displacement reaction also known as a metathesis reaction, where the anions and cations of two different molecules switch places. The third reaction, Zn + CuSO₄ → Cu + ZnSO₄, is a single displacement reaction where zinc displaces copper from copper sulfate. Lastly, the decomposition of 2Na₂O to form 4Na and O₂ represents a decomposition reactions.
When balancing equations, it's important to ensure that the number of atoms for each element is equal on both sides of the reaction. For example, to balance Mg + O₂ → MgO, you would write 2Mg + O₂ → 2MgO. Each of the other provided equations can be similarly balanced by adjusting coefficients appropriately to follow the law of conservation of mass.